#include<cstdio>
#define nmax 100010
using namespace std;
long long s;
int n,k,v[nmax],i;
int main()
{
    freopen("grupuri.in","r",stdin);
    freopen("grupuri.out","w",stdout);
    scanf("%d %d ", &k, &n);
    for(i=1;i<=n;i++)
    {scanf("%d ", &v[i]);s=(long long)(s+v[i]);}
    for(i=n;i>=1;i--)
    {
        if(v[i]<=s/k)break;
        s=(long long)(s-v[i]);
        --k;

    }
    printf("%lld", (long long)(s/k));
    return 0;
}