#include<iostream>
#include<algorithm>
#include <vector>
#include<cmath>
#include<iomanip>
#include<queue>
using namespace std;
typedef long long int lont;
int main() {
	lont A, B, C;
	cin >> A >> B >> C;
	while (A + B > C+9) {
		if (A >= 10) {
			A -= 10;
			B++;
		}
		else {
			break;
		}
	}
	lont ans = 0;
	while (A > 0 && A + B > C) {
		A--;
		ans += 1;
	}
		while (B > 0&&A+B>C) {
			B--;
			ans+=10;
		}
		if (ans) {
			cout << ans << endl;
		}
		else  {
			cout << "Impossible" << endl;
		}
	}