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

int main() {
    int a,b,c,d;
    cin>>a>>b>>c>>d;
    if (d>=10) puts("Impossible");
    else {
        int score = 0;
        int mul = 1;
        while (b >= 100) {
            score += 50*100*mul;
            b -= 100;
            mul *= 2;
        }
        score += 50*b*mul;
        if (100-b <= a) {
            score += 100*(100-b)*mul;
            a -= 100-b;
            mul *= 2;
        }
        while (a >= 100) {
            score += 100*100*mul;
            a -= 100;
            mul *= 2;
        }
        score += 100*a*mul;
        cout << score << endl;
    }
    return 0;
}