#include <iostream>
using namespace std;
int main(){
    int a,b,c,d;cin>>a>>b>>c>>d;b*=100;a*=100;
    if(d == 10){
        cout << "Impossible" << endl;
        return 0;
    }
    int nw = 1;
    int ans = 0;
    while(a+b > 0){
        if(a+b < 100){
            ans += nw*(a+b);
            break;
        }else if(b >= 100){
            ans += nw*b;
            b-=100;
        }else if(a >= 100){
            ans += nw*a;
            a-=100;
        }else{
            ans += nw*b+nw*(100-b);
            a-=b;
            b=0;
        }
        nw *= 2;
    }
    cout << ans << endl;
}