#include <iostream>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <iomanip>
#include <queue>
#include <algorithm>
#include <numeric>
#include <deque>
#include <complex>
#include <cassert>

using namespace std;
using ll = long long;

ll N, M;
vector<ll> A;

bool solve(ll c){
    ll S=0;
    for (int i=0; i<N; i++){
        if (A[i]>=c) S+= A[i]-c;
        else{
            S -= c-A[i];
            if (S < 0) return 0;
        }
    }
    return 1;
}

int main(){

    cin >> N >> M;
    A.resize(N);
    for (int i=0; i<N; i++) cin >> A[i];

    ll l=0, r=1e9+1, c;
    while(r-l>1){
        c = (l+r)/2;
        if(solve(c)) l=c;
        else r=c;
    }

    cout << l/M << endl;

    return 0;
}