1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
#include <iostream>
#include <vector>
#include <string>
using namespace std;
int main() {
	cin.tie(0);
	ios_base::sync_with_stdio(0);
	int n, k;
	cin >> n >> k;
	vector <int> c(n + 1), v(n);
	long long res = 0;
	for (auto& x : v) cin >> x;
	int cnt = 0;
	for (int i = 0; i < n && cnt < k; i++) {
		if (!c[v[i]]) {
			c[v[i]]++;
			res += i;
			res -= cnt;
			cnt++;
		}
	}
	if (cnt < k)
		res = -1;
	cout << res << "\n";
}