diff --git a/task1.cpp b/task1.cpp
new file mode 100644
index 0000000..f921a22
--- /dev/null
+++ b/task1.cpp
@@ -0,0 +1,20 @@
+#include <iostream>
+using namespace std;
+
+int main() {
+    int n;
+    cout << "Enter a four-digit number: ";
+    cin >> n;
+
+    if (n < 1000 || n > 9999) {
+        cout << "Error! This is not a four-digit number." << endl;
+    } else {
+        int a = n / 1000;
+        int b = (n / 100) % 10;
+        int c = (n / 10) % 10;
+        int d = n % 10;
+        int r = c * 1000 + d * 100 + a * 10 + b;
+        cout << "Result: " << r << endl;
+    }
+    return 0;
+}
diff --git a/task2.cpp b/task2.cpp
new file mode 100644
index 0000000..72ed94d
--- /dev/null
+++ b/task2.cpp
@@ -0,0 +1,39 @@
+#include <iostream>
+using namespace std;
+
+int main() {
+    double ab;
+    double bc;
+    double weight;
+    cout << "Distance A-B: ";
+    cin >> ab;
+    cout << "Distance B-C: ";
+    cin >> bc;
+    cout << "Cargo weight: ";
+    cin >> weight;
+
+    double fuel;
+    if (weight <= 500) fuel = 1;
+    else if (weight <= 1000) fuel = 4;
+    else if (weight <= 1500) fuel = 7;
+    else if (weight <= 2000) fuel = 9;
+    else {
+        cout << "The airplane cannot lift such a load!" << endl;
+        return 0;
+    }
+
+    double nAB = ab * fuel;
+    double nBC = bc * fuel;
+
+    if (nAB > 300) {
+        cout << "It is impossible to reach point B by flight." << endl;
+    }
+    else if (nBC > 300) {
+        cout << "It is impossible to fly from B to C." << endl;
+    }
+    else {
+        double fill = max(0.0, nBC - (300 - nAB));
+        cout << "Minimum refuel at B: " << fill << " liters." << endl;
+    }
+    return 0;
+}
diff --git a/task3.cpp b/task3.cpp
new file mode 100644
index 0000000..5694e5a
--- /dev/null
+++ b/task3.cpp
@@ -0,0 +1,55 @@
+#include <iostream>
+#include <clocale>
+using namespace std;
+
+int main() {
+    int c;
+    cout << "Menu:" << endl;
+    cout << "1. Income and delays -> lines of code" << endl;
+    cout << "2. Lines of code and desired salary -> delay" << endl;
+    cout << "3. Lines of code and delays -> salary" << endl;
+    cin >> c;
+
+    int l;
+    int t;
+    int s;
+
+    switch (c) {
+        case 1:
+            cout << "Enter the desired income ($): ";
+            cin >> s;
+            cout << "Enter the number of tardies: ";
+            cin >> t;
+            s += (t / 3) * 20;
+            l = (s / 50.0) * 100;
+            cout << "Vasyl needs to write " << l << " lines of code." << endl;
+            break;
+
+        case 2:
+            cout << "Enter the number of lines of code: ";
+            cin >> l;
+            cout << "Enter your desired salary ($): ";
+            cin >> s;
+            int b;
+            b = (l / 100) * 50;
+            cout << "Vasya can be late at most "
+                 << ((b - s) / 20) * 3 << " time(s)." << endl;
+            break;
+
+        case 3:
+            cout << "Enter the number of lines of code: ";
+            cin >> l;
+            cout << "Enter the number of tardies: ";
+            cin >> t;
+            s = (l / 100) * 50 - (t / 3) * 20;
+            if (s > 0)
+                cout << "Vasyl's salary: " << s << " $" << endl;
+            else
+                cout << "Vasya will not be paid anything." << endl;
+            break;
+
+        default:
+            cout << "Invalid choice." << endl;
+    }
+    return 0;
+}
diff --git a/task4.cpp b/task4.cpp
new file mode 100644
index 0000000..16e7745
--- /dev/null
+++ b/task4.cpp
@@ -0,0 +1,19 @@
+#include <iostream>
+#include <clocale>
+using namespace std;
+
+int main() {
+    int f;
+    cout << "Enter the finger number (1-5): ";
+    cin >> f;
+
+    switch (f) {
+        case 1: cout << "pollex" << endl; break;
+        case 2: cout << "index" << endl; break;
+        case 3: cout << "medius" << endl; break;
+        case 4: cout << "annularis" << endl; break;
+        case 5: cout << "digitus minimus" << endl; break;
+        default: cout << "Incorrect number!" << endl;
+    }
+    return 0;
+}
diff --git a/task5.cpp b/task5.cpp
new file mode 100644
index 0000000..ed74cd1
--- /dev/null
+++ b/task5.cpp
@@ -0,0 +1,35 @@
+#include <iostream>
+using namespace std;
+
+int main() {
+    double a;
+    double b;
+    double c;
+    double x;
+    double y;
+
+    cout << "Enter the edges of the brick a, b, c: ";
+    cin >> a >> b >> c;
+    cout << "Enter the hole dimensions x, y: ";
+    cin >> x >> y;
+
+    double min1 = a, min2 = b;
+
+    if (c < min1) {
+        min2 = min1;
+        min1 = c;
+    }
+    else if (c < min2) {
+        min2 = c;
+    }
+
+    if ((min1 <= x && min2 <= y) || (min1 <= y && min2 <= x)) {
+        cout << "The brick will pass through the opening." << endl;
+    }
+    else {
+        cout << "The brick won't fit through the opening.." << endl;
+    }
+
+    return 0;
+
+}