#include <iostream>
#include <fstream>
using namespace std;
int v[100001];
int main()
{
    ifstream fin ("grupuri.in");
    ofstream fout ("grupuri.out");
    int k,n,i,s=0,dr,st,m=0,max=0;
    fin>>k>>n;
    for(i=1; i<=n; i++)
    {
        fin>>v[i];
        s+=v[i];
        max=v[i];
    }
    st=1;
    dr=max*n;
    //cout<<dr;
    while(st<=dr)
    {
        m=(st+dr)/2;
        if(s<m*k)
        {
            dr=m-1;
        }
        else if (s>m*k)
            st=m+1;
        else
            dr=1;
        //cout<<m*k<<" ";
    }
    fout<<m;
    return 0;
}