rt.

#include<bits/stdc++.h>
#define fi first
#define se second
#define pii pair<int,int>
#define pll pair<ll,ll>
#define yes "Yes"
#define no "No"
#define debug(x) cout<<#x<<" = "<<x<<"\n"
#define rep(i,x,y) for(int i=x;i<=(y);++i)
#define per(i,x,y) for(int i=x;i>=(y);--i)

typedef long long ll;
typedef unsigned long long ull;

namespace fast{
	inline int sf(){
		int x=0,f=1;char c=getchar();
		while(c<'0'||c>'9'){if(c=='-')f=-1;c=getchar();}
		while(c>='0'&&c<='9'){x=(x<<1)+(x<<3)+(c^48);c=getchar();}
		return x*f;
	}
	inline void out(int n){
		if(n<0){putchar('-');n=-n;}
		if(n>9)out(n/10);
		putchar(n%10^48);
	}
}

using namespace std;
using namespace fast;

const int INF=0x3f3f3f3f;
const ll LNF=0x3f3f3f3f3f3f3f3f;
const int N=1e6+10;

int n,k;
int a[N];

bool check(ll x){
	ll sum=0;
	rep(i,1,n){
		sum+=min(0ll,(a[i]-1)-x);
	}
	return abs(sum)<=x*k;
}

void solve(){
	cin>>n>>k;
	rep(i,1,n) cin>>a[i];
	ll l=0,r=1e12,ans=0;
	while(l<=r){
		int mid=(l+r)>>1;
		if(check(mid)){
			ans=mid;
			l=mid+1;
		}else{
			r=mid-1;
		}
	} 
	cout<<ans;
}

int main(){
	int t=1;
	while(t--){
		solve();
	}
	return 0;
}