Dima and Friends

#include<stdio.h>
int main()
{
    int a,i,j=0,n,t=0;
    scanf("%d",&n);
    for(i=1;i<=n;i++)
    {
        scanf("%d",&a);
        t+=a;
    }
    for(i=1;i<=5;i++)
    {
        if((t+i)%(n+1)!=1)
            j++;
    }
    printf("%d",j);
    return 0;
}

http://codeforces.com/contest/272/problem/A