#include <fstream>
using namespace std;

ifstream fin("grupuri.in");
ofstream fout("grupuri.out");

long long n,k,i,st,dr,mid,sum,v[100001];

int main(){
    fin>>k>>n;

    for(i=1;i<=n;i++)
        fin>>v[i],sum+=v[i];

    st=1; dr=sum/k;
    while(st<=dr){
        mid=(st+dr)/2;

        sum=0;
        for(i=1;i<=n;i++)
            sum+=min(v[i],mid);

        if(sum<k*mid)
            dr=mid-1;
        else
            st=mid+1;
    }

    fout<<dr;

    return 0;
}