#include<iostream>
#include<algorithm>
#include<cmath>
#include<cstring>
using namespace std;
typedef long long ll;
const int N=1e6;
int n,k,a[N+5];
bool check(ll s){
	ll sum=0;
	for (int i=1;i<=n;i++){
		sum+=max(0ll,s-(a[i]-1));
	}
	return sum<=s*k;
}
int main(){
	scanf("%d%d",&n,&k);
	for (int i=1;i<=n;i++) scanf("%d",&a[i]);
	ll l=0,r=1e12,ans=0;
	while (l<r){
		ll mid=l+r>>1;
		if (check(mid)) ans=mid,l=mid+1;
		else r=mid-1;
	}
	printf("%lld",ans);
}