#include<stdio.h>
#define NMAX 100000
long long a[NMAX];
long long sol(long long n,long long k)
{
     if(n<0 || k<0)
        return 0;
     if(a[n]<=a[0]/k)
      return a[0]/k;
     else
     {
         a[0]-=a[n];
         return sol(n-1,k-1);
     }
}
int main()
{
    freopen("grupuri.in","r",stdin);
    freopen("grupuri.out","w",stdout);

    long long n,k;
    scanf("%lld%lld",&k,&n);

    int i;
    for(i=1; i<=n; ++i){
    scanf("%lld",&a[i]);
    a[0]+=a[i];
    }

    if(a[n]<=a[0]/k)
     printf("%lld\n",a[0]/k);
    else
     printf("%lld\n",sol(n,k));

    return 0;
}