#include <iostream>
#include <math.h>
int main(){
	int a,b;
	std::cin>>a>>b;
	int index=0;
	while(1){
		int a_=floor((a-0.5000000001)*index/100)-ceil((a+0.4999999999999)*index/100);
		int b_=floor((b-0.5000000001)*index/100)-ceil((b+0.4999999999999)*index/100);
		if(a_==-2&&b_==-2){
			break;
		}
		index++;
	}
	std::cout<<index<<std::endl;
	return 0;
}