#include <iostream>
using namespace std;

int main() {
    int a, b, c;
    cin >> a >> b >> c;
    for (int price=1;price <= a + b*10;price++) {
        for (int pa=0;pa<=a;pa++) {
            for (int pb=0;pb<=b;pb++) {
                int change = (pa + pb*10) - price;
                if (change < 0) continue;
                int ca = change % 10;
                int cb = change / 10;
                int rest = (a - pa + ca) + (b - pb + cb);
                if (rest == c) {
                    cout << price << endl;
                    return 0;
                }
            }
        }
    }
    cout << "Impossible" << endl;
    return 0;
}