#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using namespace std;
#define rep(i,n) for(int i=0;i<(n);i++)
#define Inf 1000000001


int main(){
	
	int n,m;
	cin>>n>>m;
	
	vector<long long> a(n);
	rep(i,n)cin>>a[i];
	
	long long ok = 0,ng = Inf;
	while(ng-ok>1LL){
		long long mid = (ok+ng)/2;
		long long S = 0;
		bool f = true;
		rep(i,n){
			long long t = S + a[i] - mid * m;
			if(t<0){
				f = false;
				break;
			}
			S = t;
		}
		if(f)ok = mid;
		else ng=  mid;
	}
	cout<<ok<<endl;
	
	
	return 0;
}