#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i, n) for(ll i = 0, i##_len = (n); i < i##_len; i++)
#define reps(i, s, n) for(ll i = (s), i##_len = (n); i < i##_len; i++)
#define rrep(i, n) for(ll i = (n) - 1; i >= 0; i--)
#define rreps(i, e, n) for(ll i = (n) - 1; i >= (e); i--)
#define all(x) (x).begin(), (x).end()
#define sz(x) ((ll)(x).size())
#define len(x) ((ll)(x).length())

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    // ifstream in("input.txt");
    // cin.rdbuf(in.rdbuf());
    ll a, b, c;
    cin >> a >> b >> c;
    if ((a + b + 9) < c) {
        cout << "Impossible" << endl;
        return 0;
    }
    if ((b == 0) && (a <= c)) {
        cout << "Impossible" << endl;
        return 0;
    }
    set<ll> rem;
    ll c10 = c, c1 = 0;
    while(c10 >= 0) {
        rem.insert(c10 * 10 + c1);
        c10--;
        c1++;
    }
    auto it = rem.lower_bound(a + b * 10);
    it--;
    cout << (a + b * 10 - *it) << endl;
    return 0;
}