#include<algorithm>
#include<bitset>
#include<cmath>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<ctime>
#include<deque>
#include<fstream>
#include<iomanip>
#include<iostream>
#include<map>
#include<queue>
#include<set>
#include<stack>
#include<unordered_map>
#include<unordered_set>
#include<utility>
#include<vector>

using namespace std;

#define dbg(x) (cout<<#x<<" = "<<(x)<<'\n')
#ifdef HOME
const string inputFile = "input.txt";
const string outputFile = "output.txt";
#else
const string problemName = "grupuri";
const string inputFile = problemName + ".in";
const string outputFile = problemName + ".out";
#endif

typedef long long int lld;
typedef pair<int, int> PII;
typedef pair<int, lld> PIL;
typedef pair<lld, int> PLI;
typedef pair<lld, lld> PLL;

const int INF = (1LL << 29) - 1;
const lld LINF = (1LL << 62) - 1;
const int dx[] = {1, 0, -1, 0, 1, -1, 1, -1};
const int dy[] = {0, 1, 0, -1, 1, -1, -1, 1};
const int NMAX = 100000 + 5;

int N, K, sol;
int A[NMAX];
lld S;

bool check(int p) {
    int i, ok = 0;
    lld t = 0;

    for(i = N; i >= 1 && ok < K; i--)
        if(A[i] >= p)
            ok++;
        else {
            t += A[i];
            ok += t / p;
            t %= p;
        }

    return (ok >= K);
}

int main() {
    int i, lo, mi, hi;

#ifndef ONLINE_JUDGE
    freopen(inputFile.c_str(), "r", stdin);
    freopen(outputFile.c_str(), "w", stdout);
#endif

    scanf("%d%d", &K, &N);

    for(i = 1; i <= N; i++) {
        scanf("%d", &A[i]);
        S += A[i];
    }

    for(lo = 1, hi = S / K; lo <= hi; ) {
        mi = (lo + hi) / 2;

        if(check(mi)) {
            lo = mi + 1;
            sol = mi;
        } else
            hi = mi - 1;
    }

    printf("%d\n", sol);

    return 0;
}