#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

ll C[10];

int main()
{
    ll B, N; cin >> B >> N;

    ll sum = 0;

    for (ll i = 0; i < N; ++i) {
        cin >> C[i];
        sum += C[i];
    }

    ll avg = sum / N;

    ll ans = 0;

    for (ll i = 0; i < N; ++i) {
        if (C[i] > avg) ans += C[i] - avg;
        if (C[i] < avg) ans += avg - C[i];
    }

    cout << ans << endl;
}