23 lines
404 B
C++
23 lines
404 B
C++
#include <bits/stdc++.h>
|
|
|
|
using namespace std;
|
|
const int MOD = 1000000007;
|
|
typedef long long LL;
|
|
/*
|
|
3 5 4
|
|
|
|
36
|
|
*/
|
|
int main() {
|
|
LL n, m, k;
|
|
cin >> n >> m >> k;
|
|
// k=4 m=5
|
|
LL a = ((k - 1) * (m - k + 1)) % MOD;
|
|
|
|
// LL b = 0;
|
|
// for (LL i = 1; i <= n; i++) b = (b + i) % MOD;
|
|
LL b = (n * (n + 1) / 2) % MOD;
|
|
|
|
cout << (a * b) % MOD << endl;
|
|
return 0;
|
|
} |