// UUID: 88a52e97-6101-486b-a8d2-01b16d05e65e
#include <bits/stdc++.h>
using namespace std;
vector<int> prices;
long full_price=0;
int item_price;
int avg;
int db;
int eredmény=0;
int main() {
    cin>>db;
    cin>>avg;
    avg=avg*db;
    
    prices.reserve(db);

    while(cin>>item_price){
        full_price+=item_price;
        prices.push_back(item_price);
    }
    if (full_price<avg){
        cout<<'1';
    }
    else if(full_price==avg){
        cout<<'0';
    }
    else{
        long diff{full_price - avg};
        while(diff>0){
            auto iter{std::max_element(prices.begin(), prices.end())};
            int max {*iter};
            *iter = 0;
            diff-=max-1;
            eredmény+=1;

        }
        cout<<eredmény;
    }
}