272A - Dima and Friends - CodeForces Solution

#include<bits/stdc++.h>

#define ll long long
#define debug(x) cout<<#x<<" : "<<x<<'\n';
#define debugarr(x) for(auto i:x)cout<<i<<endl;
using namespace std;
const int MOD = 1e9+7;


int main()
{
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    int n, temp, x = 0, ans = 0;
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> temp;
        x += temp;
    }
    
    for (int i = 1; i < 6; i++) {
        if ( (x + i) % (n + 1) == 1) ans++;
    }
    cout << 5 - ans << '\n';


    return 0;
}