Jubilee

#include <bits/stdc++.h>

using namespace std;

using ll = long long;

const ll MOD   = 1e9 + 7;

int main()
{
    ios_base::sync_with_stdio(false);

    ll n, m;
    cin >> n >> m;

    if (m == 1)
    {
        cout << 0 << '\n';
        return 0;
    }

    ll answer = m * (m - 1) % MOD;
    for (ll i = 1; i < n; i++)
    {
        ll first = 0;
        first = (answer * (m - 1)) % MOD;
        ll second = 0;
        if (m >= 3)
            second = (answer * (((m - 2) * (m - 2)) % MOD)) % MOD;
        answer = (first + second) % MOD;
    }
    cout << answer << '\n';

    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

Test 14

Verdict: ACCEPTED