#include <bits/stdc++.h>
using namespace std;
using ll = long long;


bool func(vector<ll>& a, int n, ll m, ll mid){
    ll s = 0;
    ll t = mid * m;
    for(int i = 0; i < n; ++i){
        s += a[i];
        if(s < t * (i + 1)){
            return false;
        }
    }
    return true;
}


int main(){
    int n;  ll m;   cin >> n >> m;
    vector<ll> a(n);
    for(auto& x : a){
        cin >> x;
    }

    ll ok = 0;
    ll ng = 1000000001;
    while(abs(ok - ng) > 1){
        ll mid = (ok + ng) / 2;
        if(func(a, n, m, mid)){
            ok = mid;
        }
        else{
            ng = mid;
        }
    }
    cout << ok << endl;

    return 0;
}