#include <iostream>
using namespace std;

int main(){
    // when you have something that you are gonna be using as a sum of some numbers, you set it like a 0
    // when you have something that you are gonna be using as a product of some numbers, you set it like a 1
    // in this case we have result = 1, because I'll use it like a product

    int n;
    cout << "Enter a number: ";
    cin >> n;
    int num = 1;
    cout << num;
    for(int i = 1; i < n; i++){
        num = num * 10 + 1;
        cout << " + " << num;
    }




    int sum = 0;

    for(int i = 100; i <= 200; i++){
        if(i % 9 == 0){
            sum += i;
        }
    }

    cout << "The sum is " << sum << endl;




    int number, lastDigit, reverse = 0;

    cout << "Enter a number: ";
    cin >> number;

    do {
        lastDigit = number % 10;
        reverse = (reverse * 10) + lastDigit;
        number /= 10;
    } while(number != 0);

    cout << "Reverse: " << reverse << endl;




    int number, lastDigit, reverse = 0;

    cout << "Enter a number: ";
    cin >> number;

    int n = number;

    do {
        lastDigit = number % 10;
        reverse = (reverse * 10) + lastDigit;
        number /= 10;
    } while(number != 0);

    if(n == reverse){
        cout << "Yes, it's a palindrome. " << endl;
    } else {
        cout << "No, it's not a palindrome. " << endl;
    }


    // check if the first digit is the same as the lastDigit

    int number;
    cout << "Enter a number: ";
    cin >> number;
    int temp = number, firstDigit, lastDigit = number % 10;
    while(temp != 0){
        if(temp < 10){
            temp = firstDigit;
        }
        temp /= 10;
    }

    cout << "First digit of a number is " << firstDigit << endl;
    cout << "Last digit of a number is " << lastDigit << endl;

    if(firstDigit == lastDigit){
        cout << "The digits are equal!" << endl;
    } else {
        cout << "The digits aren't equal!" << endl;
    }


    int number;
    cout << "Enter a number: ";
    cin >> number;


    for(int i = 2; i < number / 2; i++){
        if(number % i == 0){
            bool flag = true;
            for(int j = 2; j < i / 2; j++){
                if(i % j == 0){
                    flag = false;
                }
            }
            if(flag){
                cout << i << " ";
            }
        }
    }



    double a, b, c;

    for(size_t i = 1; i <= 50; i++){
        c = i;
        for(size_t j = 1; j <= 50; j++){
            b = j;
            for(size_t k = 1; k <= 50; k++){
                a = k;
                if(c * c * c == a * a + b * b){
                    cout << a << " ," << b << " ," << c << endl;
                }
            }
        }
    }




    int x, y, x1, y1, radius;
    cin >> x >> y >> x1 >> y1 >> radius;
    bool isInCircle = ((x - x1) * (x - x1) + (y - y1) * (y - y1)) <= raidus * radius;
    cout << boolalpha << isInCircle << endl;




    int low, high, i;
    bool flag = true;

    cout << "Enter an interval: ";
    cin >> low >> high;

    while(low < high){
        flag = true;
        if(low == 0 || low == 1){
            flag = false;
        }

        for(i = 2; i <= low / 2; i++){
            if(low % i == 0){
                flag = false;
                break;
            }
        }

        if(flag){
            cout << low << " ";
        }
        low++;
    }


    cout << "Enter 10 characters: " << endl;

    int n;
    int countLowerCases = 0;
    int countUpperCases = 0;
    int countDigits = 0;

    cin >> n;

    for(int i = 0; i < n; i++){
        if(i >= 'a' && i <= 'z'){
            countLowerCases++;
        } else if(i >= 'A' && i <= 'Z'){
            countUpperCases++;
        } else if(i >= '0' && i <= '9'){
            countDigits++;
        }
    }

    cout << "Count lower cases: " << countLowerCases << endl;
    cout << "Count upper cases: " << countUpperCases << endl;
    cout << "Count digits: " << countDigits << endl;

    return 0;
}