#include <iostream>
#include <cstdio>
using namespace std;
int a[100001];
long long n,k,st,dr,mij,sum,rez,i;
int main()
{
    freopen("grupuri.in","r",stdin);
    freopen("grupuri.out","w",stdout);
    cin>>k>>n;
    for(i=1;i<=n;i++)
        cin>>a[i];
    st=1;
    dr=100000000001;
    while(st<=dr)
    {
        sum=0;
        mij=(st+dr)/2;
        for(i=1;i<=n;i++)
        if(a[i]<mij)
            sum+=a[i];
        else
            sum+=mij;
        if(sum<k*mij)
            dr=mij-1;
        else
        {
            rez=mij;
            st=mij+1;
        }
    }
    cout<<rez;
    return 0;
}