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

int main() {
    int N,M;
    cin >> N >> M;
    vector<int>A(N);
    for(int i = 0; i < N; i++) {
        cin >> A[i];
    }
    int l = 0,r = 1001001001/M+1;
    while (l+1 < r) {
        int mid = (l+r)/2;
        int tmp = mid*M;
        long long sum = 0;
        bool flag = true;
        for(int i = 0; i < N; i++) {
            if(sum+A[i] >= tmp) {
                sum = sum+A[i]-tmp;
            }
            else {
                flag = false;
            }
        }
        if(flag) {
            l = mid;
        }
        else {
            r = mid;
        }
    }
    cout << l << endl;
}