为啥MLE

是啥原因？

#include <iostream>
#include <cstdio>
#include <cmath>
using namespace std;
#define int long long
int a;
const int mod = 1e9 + 7;
int qpow(int a, int b) {
	int s = 1;
	while (b) {
		if (b & 1) s = s * a % mod;
		a = a * a % mod;
		b >>= 1;
	}
	return s;
}

signed main() {
	int n;
	scanf("%lld", &n);
	for (int i = 0; i < n; i++) {
		int t;
		scanf("%lld%lld",&a,&t);
		if(t==1 && a != 2) {
		   printf("%lld\n" , 2 * a % mod);
		    continue;
		}
		if (a == 1) a = 2, t--;
		if (a == 2) {
			a = 3, t --;
		}
	cout << (qpow(2, t) % mod * a) % mod << endl;
	}

	return 0;
}
/*
355098215
*/