本蒟蒻试着计算每个旅馆的贡献，没有T掉，但全WA了。。。

#include <iostream>
#include <vector>
using namespace std;
const int maxn = 2e5+5;
int n, k, p;
int a[maxn], b[maxn];
int pre[maxn];
vector<int> color[55];
int main() {
    cin >> n >> k >> p;
    for (int i = 1; i <= n; i++) {
        cin >> a[i] >> b[i];
        color[a[i]].push_back(i);
    }
    for (int i = 1; i <= n; i++) {
        pre[i] = pre[i - 1] + (b[i] <= p);
    }
    int ans = 0;
    for (int i = 0; i < k; i++) {
        for (int j = 0; j < color[i].size() - 1; j++) {
            ans += (j + 1) * (color[i].size() - j - 1) * (bool)(pre[color[i][j + 1]] - pre[color[i][j] - 1]);
        }
    }
    cout << ans << endl;
    return 0;
}