//=================================
// Created on: 2018/10/19 21:42:47
//=================================
#include <bits/stdc++.h>
int main()
{
    int A, B, C, D;
    std::cin >> A >> B >> C >> D;
    int score = 0, c = 0, b = 1;
    if (D == 10) { return std::cout << "Impossible" << std::endl, 0; }
    for (int i = 0; i < B; i++) {
        if (c >= 100) { b *= 2, c = 0; }
        score += 50 * b, c++;
    }
    for (int i = 0; i < A; i++) {
        if (c >= 100) { b *= 2, c = 0; }
        score += 100 * b, c++;
    }
    std::cout << score << std::endl;
    return 0;
}