#include <cstdio>

using namespace std;

long long v[100001];

int main()
{
    int i,k,n;
    freopen("grupuri.in","r",stdin);
    freopen("grupuri.out","w",stdout);
    scanf("%d %d\n",&k,&n);
    for(i=1;i<=n;++i)
    {
        scanf("%lld\n",&v[i]);
        v[i]+=v[i-1];
    }
    while (v[n]-v[n-1]>v[n]/k)
    {
        --n;
        --k;
    }
    printf("%lld\n",v[n]/k);
    return 0;
}