#include<fstream>
using namespace std;
unsigned long long v[100010],i,n,k,s,m,d,sol;
unsigned long long S,sum;

int main()
{
ifstream f("grupuri.in");
ofstream g("grupuri.out");

f>>k>>n;

for(i=1;i<=n;i++) {f>>v[i]; S+=v[i];}

d=S/k; s=1;

while(s<=d)

 { m=(s+d)>>1;

   S=0; sum=k*m; i=0;

    while(S<sum&&i<n)

     {  i++;

        if(v[i]<=m) S+=v[i];

           else S+=m;
     }

   if(S>=sum) {s=m+1;  sol=m;}

     else d=m-1;
  }

g<<sol;
f.close();
g.close();
return 0;
}