#include<iostream>
#include<string>

int main(void){
	std::string h,s;
	std::cin>>h>>s;
	if(h.back() % 1 == s.back() % 1){
		std::cout << "Possible" << std::endl;
	}
	else
	{
		std::cout << "Impossible" << std::endl;
	}
}