#define _USE_MATH_DEFINES
#include <cstdio>
#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <complex>
#include <string>
#include <vector>
#include <array>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <limits>
#include <climits>
#include <cfloat>
#include <functional>
#include <iterator>
#include <memory>
#include <regex>
using namespace std;

int main()
{
    int a, b, c, d;
    cin >> a >> b >> c >> d;
    if(d >= 10){
        cout << "Impossible" << endl;
        return 0;
    }

    long long ans = 0;
    for(int i=0; a+b>0; ++i){
        int y = min(100, b);
        int x = min(a, 100 - y);
        long long tmp = 100 * x + 50 * y;
        tmp *= 1 << i;
        ans += tmp;
        a -= x;
        b -= y;
    }
    cout << "Possible" << endl << ans << endl;

    return 0;
}