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

int calc(int x) {
	return x / 10 + x % 10;
}

int main()
{
	int A, B, C;
	cin >> A >> B >> C;
	bool ok = false;
	int res = 100000;
	for (int i = 0; i <= A; i++) {
		for (int j = 0; j <= B; j++) {
			int v = i + j * 10;
			for (int k = 1; k <= v; k++) {
				if (A - i + B - j + calc(v - k) == C) {
					ok = true;
					res = min(res, k);
				}
			}
		}
	}
	if (!ok) cout << "Impossible" << endl;
	else cout << res << endl;
	return 0;
}