签到题看错模数。。。 1e8+7 什么鬼

#include <stdio.h>
#include <iostream>

typedef long long ll;
using namespace std;
const ll Mod = 1e8+7;

ll n, m, i, j, k;

ll qp(ll a, ll b) {
    ll res = 1;
    while(b) {
        if(b & 1) res = res*a % Mod;
        a = a*a % Mod;
        b >>= 1;
    }
    return res;
}
ll inv(ll x) { return qp(x, Mod-2); }
ll C(ll n, ll m) {
    ll ans = 1, div = 1;
    for(i = n-m+1; i <= n; ++i) ans = ans*i % Mod;
    for(i = 2; i <= m; ++i) div = div*i % Mod;
    return ans*inv(div) % Mod;
}
int main() {
    cin >> n >> m;
    m = min(m, n-m);
    cout << C(n, m);
    return 0;
}