#include<bits/stdc++.h>
using namespace std;
using ll = long long int;
using ld = long double;
#define pow(n,m) powl(n,m);
#define sqrt(n) sqrtl(n);
const ll MAX = 5000000000000000000;
const ll MOD = 1000000007;
//998244353;
void randinit(){srand((unsigned)time(NULL));}
int main(){
    ll N,i,a,s = 0;
    cin >> N;
    for(i = 0;i < N - 1;i++){
        cin >> a;
        s = a;
    }
    a = 0;
    for(i = 0;i <= 100;i++){
        if((s + i) % N == 0) a++;
    }
    cout << a << endl;
}