#include <iostream>

using namespace std;

int solve(int a, int b, int c) {
  if (a + b < c) {
    int k = c - a - b;
    int l = k / 9 + 1;
    a += 10 * l;
    b -= l;
    int m = (a - (c-b)) / 10;
    int n = a - 10*m;
    int o = n - (c - b - m);
    if (o < 10 * (l - 1)) {
      return -1;
    }
    return n - (c - b - m);
  }
  else if (b >= c) return 10 * (b-c) + a;
  else {
    int k = (a - (c-b)) / 10;
    int l = a - 10*k;
    return l - (c - b - k);
  }
}

int main() {
  int a, b, c;
  int answer = 0;
  cin >> a >> b >> c;
  answer = solve(a, b, c);
  if (answer <= 0) cout << "Impossible" << endl;
  else cout << answer  << endl;

  return 0;
}