#include <iostream>
#include <cstdio>
using namespace std;
typedef long long LL;
const LL mod = 1e9 + 7;
LL pow_mod(LL a, LL b) {
    LL res = 0; //这里需要修改 
    while (b > 0) {
        a = a * a % mod; //这行代码需要移到合适的位置 
        if (b & 1) {
            /*这里需要添加合适的代码*/
        }
        
        b >>= 1;
    }
    return res;
}
int main() {
    freopen("balloon.in", "r", stdin);
    freopen("balloon.out", "w", stdout);
    LL n, m;
    cin >> n >> m;
    cout <</*这里需要添加合适的代码*/<< endl;
    return 0;
}