#include <fstream>
using namespace std;
ifstream fin("grupuri.in");
ofstream fout("grupuri.out");

long long i, j, n, m, st, dr, k, mid, v[100010];

int verif(long long p){
    long long s=0;
    for(int i=1; i<=n; i++){
        s+=min(v[i], p);
    }
    if(s<p*k){
        return 0;
    }else{
        return 1;
    }
}

int main(){
    fin>>k>>n;
    for(i=1; i<=n; i++){
        fin>>v[i];
    }
    st=1;
    dr=2000000000;
    while(st<=dr){
        mid=(st+dr)/2;
        if(verif(mid)==0){
            dr=mid-1;
        }else{
            st=mid+1;
        }
    }
    fout<<dr;
}