#include <iostream>
using namespace std;
int main(int argc, char* argv[])
{
	int A,B,C,D;
	int aV=100;
	int bV=50;
	int dV=-100;
	cin>>A>>B>>C>>D;
	if (D*100>=1000){
		cout<<"Impossible"<<endl;
		return 0;
	}
	int Sum=0;
	if (A<100){
		Sum+=A*aV;
	}else{	
		Sum+=100*aV;
		A-=100;
		int num=2*aV;
		while (A>=100){
			Sum+=100*num;
			A-=100;
			num*=2;
		}
		Sum+=A*num;
	}
	if (B<100){
		Sum+=B*bV;
	}else{	
		Sum+=100*bV;
		B-=100;
		int num=2*bV;
		while (B>=100){
			Sum+=100*num;
			B-=100;
			num*=2;
		}
		Sum+=B*num;
	}
	cout<<Sum<<endl;
	return 0;
}