#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
  #include "settings/debug.cpp"
#else
  #define Debug(...) void(0)
#endif
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

inline int returned(int a, int b, int c) {
  int rem = a + 10 * b - c;
  if (rem < 0) return -1e9;
  return rem / 10 + rem % 10;
}

int main() {
  int a, b, c;
  cin >> a >> b >> c;
  rep(cost, 300) {
  	if (cost == 0) continue;
    rep(a_used, a + 1) rep(b_used, b + 1) {
      int num = 0;
      num += a - a_used;
      num += b - b_used;
      num += returned(a_used, b_used, cost);
      if (num == c) {
        cout << cost << endl;
        return 0;
      }
    }
  }
  cout << "Impossible" << endl;
  return 0;
}