diff --git a/2sem/programming basics/20/100.cpp b/2sem/programming basics/20/100.cpp
new file mode 100644
index 0000000..a2d7834
--- /dev/null
+++ b/2sem/programming basics/20/100.cpp	
@@ -0,0 +1,219 @@
+// pb_18_100.cpp
+// Горбацевич Андрей
+#include <iostream>
+#include <fstream>
+#include <vector>
+#include <iomanip>
+#include <cstring>
+
+class DB_record {
+    std::string surname = "";
+    unsigned short age = 0;
+    std::string city = "";
+    enum scholarship {
+        HI_ED = 0, SC_ED = 1, SV_RD = 2
+    } scs = SV_RD;
+
+public:
+    DB_record() = default;
+
+    void load_txt(std::istream &ist) {
+        ist >> this->surname;
+        if (this->surname.length() > 32) {
+            this->surname = this->surname.substr(0, 32);
+        }
+        ist >> this->age;
+        ist >> this->city;
+        if (this->city.length() > 32) {
+            this->city = this->city.substr(0, 32);
+        }
+        {
+            std::string comp_str;
+            ist >> comp_str;
+            if (comp_str[0] == '"') {
+                std::string sub_comp_str;
+                ist >> sub_comp_str;
+                comp_str += " " + sub_comp_str;
+            }
+            if (comp_str == "higher") {
+                this->scs = HI_ED;
+            }
+            else if (comp_str == "secondary") {
+                this->scs = SC_ED;
+            }
+            else if (comp_str == "\"secondary vocational\"") {
+                this->scs = SV_RD;
+            }
+        }
+    }
+
+    void load_bin(std::istream &ist) {
+        struct wrapper {
+            char _surname[32];
+            unsigned short _age;
+            char _city[32];
+            scholarship _scs;
+        } wr{};
+        ist.read(reinterpret_cast<char*>(&wr), sizeof(wrapper));
+
+        this->surname = std::string(wr._surname);
+        this->age = wr._age;
+        this->city = std::string(wr._city);
+        this->scs = wr._scs;
+    }
+
+    void save_bin(std::ostream &ost) const {
+        struct wrapper {
+            char _surname[32];
+            unsigned short _age;
+            char _city[32];
+            scholarship _scs;
+        } wr{};
+        std::strcpy(wr._surname, this->surname.c_str());
+        wr._age = this->age;
+        std::strcpy(wr._city, this->city.c_str());
+        wr._scs = this->scs;
+
+        ost.write(reinterpret_cast<char*>(&wr), sizeof(wrapper));
+    }
+
+    static void print_table_head(std::ostream &ost) {
+        ost.setf(std::ios::left);
+        ost << std::string(102, '=') << std::endl;
+        ost << std::setw(34) << "| surname";
+        ost << std::setw(8) << " | age";
+        ost << std::setw(35) << " | city";
+        ost << std::setw(23) << " | scholarship" << " |\n";
+        ost << std::string(102, '=') << std::endl;
+    }
+
+    void print_table_row(std::ostream &ost) const {
+        ost.setf(std::ios::left);
+        ost << "| " << std::setw(32) << this->surname;
+        ost << " | " << std::setw(5) << this->age;
+        ost << " | " << std::setw(32) << this->city;
+        ost << " | " << std::setw(20);
+        switch (this->scs) {
+            case HI_ED:
+                ost << "higher";
+                break;
+            case SC_ED:
+                ost << "secondary";
+                break;
+            case SV_RD:
+                ost << "secondary vocational";
+                break;
+        }
+        ost << " |\n";
+    }
+
+    bool validate() {
+        return this->surname.length() > 0 && this->age > 0 && this->city.length() > 0;
+    }
+};
+
+typedef std::vector<DB_record> Database;
+
+std::size_t print_table(const Database &data, std::ostream &ost) {
+    std::size_t c = 0;
+    DB_record::print_table_head(ost);
+    for (const auto& rec : data) {
+        rec.print_table_row(ost);
+        c++;
+    }
+    return c;
+}
+
+std::size_t load_txt(Database &data, std::istream &ist) {
+    std::size_t c = 0;
+    while (!ist.fail() && !ist.eof()) {
+        DB_record record{};
+        record.load_txt(ist);
+        if (record.validate()) {
+            data.push_back(record);
+            c++;
+        }
+    }
+    return c;
+}
+
+std::size_t load_bin(Database &data, std::istream &ist) {
+    std::size_t c = 0;
+    while (!ist.fail() && !ist.eof()) {
+        DB_record record{};
+        record.load_bin(ist);
+        if (record.validate()) {
+            data.push_back(record);
+            c++;
+        }
+    }
+    return c;
+}
+
+std::size_t save_bin(const Database &data, std::ostream &ost) {
+    std::size_t c = 0;
+    for (const auto& rec : data) {
+        rec.save_bin(ost);
+        c++;
+    }
+    return c;
+}
+
+void first_mode(std::string &path_in, std::string &path_out) {
+    std::ifstream ist(path_in);
+    std::ofstream ost(path_out, std::ios::binary);
+    if (!ist.is_open())
+    {
+        std::cerr << "Unable to open file" << std::endl;
+    }
+    else {
+        Database db;
+        std::size_t trrc = load_txt(db, ist);
+        std::cout << "Read " << trrc << " rows from txt\n";
+        std::size_t prc = print_table(db, std::cout);
+        std::cout << "Print " << prc << " rows from db\n";
+        std::size_t brwc = save_bin(db, ost);
+        std::cout << "Write " << brwc << " rows to bin\n";
+    }
+    ist.close();
+    ost.close();
+}
+
+void second_mode(std::string &path_in) {
+    std::ifstream ist(path_in, std::ios::binary);
+    if (!ist.is_open())
+    {
+        std::cerr << "Unable to open file" << std::endl;
+    }
+    else {
+        Database db;
+        std::size_t brrc = load_bin(db, ist);
+        std::cout << "Read " << brrc << " rows from bin\n";
+        std::size_t prc = print_table(db, std::cout);
+        std::cout << "Print " << prc << " rows from db\n";
+    }
+    ist.close();
+}
+
+int main() {
+    std::string path_in = "in.txt"; // путь до входного файла
+    std::string path_out = "out.bin"; // путь до выходного файла
+
+    std::cout << "Select working mode:\n\t1. First mode\n\t2. Second mode\n>>> ";
+    int mode;
+    std::cin >> mode;
+    switch (mode) {
+        case 1:
+            first_mode(path_in, path_out);
+            break;
+        case 2:
+            second_mode(path_out);
+            break;
+        default:
+            std::cerr << "WRONG MODE SELECTED. SHOULD BE 1 OR 2\n";
+            break;
+    }
+
+    return 0;
+}
+