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

int main() {
  int a, b, c;
  cin >> a >> b >> c;
  bool check = false;
  int ans = 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 + (v - k) / 10 + (v - k) % 10 == c) {
          check = true;
          ans = min(ans, k);
        }
      }
    }
  }
  if (check) cout << ans << endl;
  else cout << "Impossible" << endl;
  return 0;
}