# include <bits/stdc++.h>
using namespace std;
ifstream fi("grupuri.in");
ofstream fo("grupuri.out");
int s[100005];
int n,k;
bool merge(long long x)
{
    long long S=0;
    for (int i=1;i<=n;++i) S+=min(1LL*s[i],x);
    return (S >= 1LL * x * k);
}
int main(void)
{
    fi>>k>>n;
    for (int i=1;i<=n;++i) fi>>s[i];
    long long p=0,u=1e11;
    long long Sol;
    while (p < u)
    {
        long long m=(p+u)/2;
        if (merge(m)) Sol=m,p=m+1;else u=m;
    }
    return fo << Sol << '\n',0;
}