#include <iostream>
using namespace std;

int main()
{
    int k, n, res=0;
    cin >> k >> n;
    int *mas = new int[n];

    for (int i=0; i!=n; i++)
    {
        cin >> mas[i];

        if (mas[i] > k)
        {
            res = res + (mas[i] - k);
        }
        else
        {
            if (res!=0 )
            {
                if ((k - mas[i]) > res)
                {
                    res = 0;
                }
                else
                {
                    res = res - (k - mas[i]);
                }
            }
        }

    }
    cout << res;

    return 0;
}

This is the mean.

Edited by author 17.01.2018 14:44