#include <stdio.h>
#define MAX 100000
 
int a[MAX], n, k;
 
int bin_search(int, int);
int test(int);
 
int main()
{
    long long sum = 0;
    int i, m, st, dr, sol = 0;
 
    freopen("grupuri.in", "r", stdin);
    freopen("grupuri.out", "w", stdout);
 
    scanf("%d %d", &k, &n);
 
    for(i=0;i<n;++i)
    {
        scanf("%d", &a[i]);
        sum += a[i];
    }
 
    st = a[n-k];
    dr = sum/k;
 
    while(st<=dr)
    {
        m = (st + dr)/2;
 
        if(test(m))
        {
            st = m+1;
            sol = m;
        }
        else
        {
            dr = m-1;
        }
    }
 
    printf("%d", sol);
 
    return 0;
}
 
int test(int nrg)
{
    int col = 0, lin = 0, i = 0;
 
    while(col < k)
    {
        if(i == n)
        {
            return 0;
        }
 
        if(a[i] >= nrg)
        {
            col += n-i;
            if(col >= k)
            {
                return 1;
            }
            return 0;
        }
        else
        {
 
            lin += a[i];
            if(lin >= nrg)
            {
                lin -= nrg;
                col++;
            }
        }
 
        i++;
    }
 
    return 1;
 
}