B2074 为什么错，求大佬解

#include <bits/stdc++.h>
using namespace std ;

int main()
{
	int a , b ;
	cin >> a >> b ;
	int num = pow(a,b) ;
	 
	if ( num % 7 == 0 )	cout << "Sunday" << endl ;
	else if ( num % 7 == 1 )	cout << "Monday" << endl ;
	else if ( num % 7 == 2 )	cout << "Tuesday" << endl ;
	else if ( num % 7 == 3 )	cout << "Wednesday" << endl ;
	else if ( num % 7 == 4 )	cout << "Thursday" << endl ;
	else if ( num % 7 == 5 )	cout << "Friday" <<endl ;
	else if ( num % 7 == 6 )	cout << "Saturday" <<endl ;
	
	return 0 ;
}