بهداشت و سلامت

Main.cpp

#include <iostream>

using namespace std;

int main()
{
    int n, x;
    
    cin >> n;
    cin >> x;
    
    switch(x){
        case 0:
            cout << 20;
            break;
        case 7:
            cout << n;
            break;
        default:
            n = n - x;
            int res = n < 0 ? 0 : n;
            cout << res;
            break;
    }

    return 0;
}