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

typedef long long int ll;
typedef pair<ll, ll> pll;

#define FOR(i, n, m) for (ll(i) = (m); (i) < (n); ++(i))
#define REP(i, n) FOR(i, n, 0)
#define OF64 std::setprecision(10)

const ll MOD = 1000000007;
const ll INF = (ll)1e15;

int main()
{
    ll A, B, C;
    cin >> A >> B >> C;
    ll sum = A + 10 * B;
    FOR(i, sum + 1, 1)
    {
        ll b = (sum - i) / 10;
        ll a = (sum - i) % 10;
        if (a + b == C)
        {
            cout << i << endl;
            return 0;
        }
    }
    cout << "Impossible" << endl;
    return 0;
}