diff --git a/1sem/programming basics/z14/40.cpp b/1sem/programming basics/z14/40.cpp
new file mode 100644
index 0000000..275e9d7
--- /dev/null
+++ b/1sem/programming basics/z14/40.cpp	
@@ -0,0 +1,32 @@
+// pb_z14_40.cpp
+// Горбацевич Андрей
+#include <iostream>
+#include <fstream>
+
+using namespace std;
+
+void write_aa_55(ostream &ost, size_t N);
+
+int main() {
+    ifstream inf("in.txt");
+    ofstream fout("out.bin", ios::trunc|ios::binary);
+    if (!inf.is_open() || !fout.is_open())
+    {
+        cerr << "Unable to open file" << endl;
+        return 1;
+    }
+
+    int N = 0;
+    inf >> N;
+    write_aa_55(fout, N);
+    return 0;
+}
+
+void write_aa_55(ostream &ost, size_t N) {
+    for (size_t i = 0; i < N; i +=2) {
+        ost << (unsigned char)0xAA;
+        if (i + 1 < N) {
+            ost << (unsigned char)0x55;
+        }
+    }
+}
diff --git a/1sem/programming basics/z14/41.cpp b/1sem/programming basics/z14/41.cpp
new file mode 100644
index 0000000..711114d
--- /dev/null
+++ b/1sem/programming basics/z14/41.cpp	
@@ -0,0 +1,35 @@
+// pb_z14_41.cpp
+// Горбацевич Андрей
+#include <iostream>
+#include <fstream>
+
+using namespace std;
+
+void write_cyclic_one(ostream &ost, size_t N);
+
+int main() {
+    ifstream inf("in.txt");
+    ofstream fout("out.bin", ios::trunc|ios::binary);
+    if (!inf.is_open() || !fout.is_open())
+    {
+        cerr << "Unable to open file" << endl;
+        return 1;
+    }
+
+    int N = 0;
+    inf >> N;
+    write_cyclic_one(fout, N);
+    return 0;
+}
+
+void write_cyclic_one(ostream &ost, size_t N) {
+    unsigned char cval = 0x01;
+    unsigned char mval = 0x80;
+    for (size_t i = 0; i < N; i +=2) {
+        if (cval >= mval) {
+            cval = 0x01;
+        }
+        ost << cval;
+        cval <<= 1u;
+    }
+}
diff --git a/1sem/programming basics/z14/42.cpp b/1sem/programming basics/z14/42.cpp
new file mode 100644
index 0000000..024de69
--- /dev/null
+++ b/1sem/programming basics/z14/42.cpp	
@@ -0,0 +1,35 @@
+// pb_z14_42.cpp
+// Горбацевич Андрей
+#include <iostream>
+#include <fstream>
+
+using namespace std;
+
+void write_filling_ones(ostream &ost, size_t N);
+
+int main() {
+    ifstream inf("in.txt");
+    ofstream fout("out.bin", ios::trunc|ios::binary);
+    if (!inf.is_open() || !fout.is_open())
+    {
+        cerr << "Unable to open file" << endl;
+        return 1;
+    }
+
+    int N = 0;
+    inf >> N;
+    write_filling_ones(fout, N);
+    return 0;
+}
+
+void write_filling_ones(ostream &ost, size_t N) {
+    unsigned char cval = 0b00000000;
+    unsigned char mval = 0b11111111;
+    for (size_t i = 0; i < N; i +=2) {
+        if (cval == mval) {
+            cval = 0b00000000;
+        }
+        ost << cval;
+        cval = (unsigned)(cval << 1u) | 1u;
+    }
+}