Driving

#include <bits/stdc++.h>

#define i64 long long
#define u64 unsigned long long
#define i32 int
#define u32 unsigned int

#define pii pair<int, int>
#define pll pair<long long, long long>

#define ld long double
#define defmod 1000000007

#define mati64(a,b) vector<vector<i64>>(a, vector<i64>(b, 0));
using namespace std;


int main(){
	cin.sync_with_stdio(0);
	cin.tie(0);
	
	i64 n, p; cin >> n >> p;
	i64 a[101010];
	for(int i = 0; i < n; ++i)
		cin >> a[i];
	sort(a, a+n);
	i64 ma = 0;
	for(int i = 0; i < n; ++i){
		ma = max(ma, p*(i+1)-a[i]+a[0]);
	}
	cout << ma << endl;
	return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED