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

template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

#define FOR(i,a,b) for(ll i=(a);i<(b);++i)
#define ALL(v) (v).begin(), (v).end()
#define p(s) cout<<(s)<<endl
#define p2(s, t) cout << (s) << " " << (t) << endl
#define br() p("")
#define pn(s) cout << (#s) << " " << (s) << endl

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    // input
    ll A, B, C;
    cin >> A >> B >> C;

    ll max_price = A + 10*B;
    FOR(price, 1, max_price+1){
        // それの支払い方
        FOR(i, 0, A+1){
            FOR(j, 0, B+1){
                ll hand = i + 10*j; // 出す

                if(hand<price) continue;

                ll change = hand - price;
                ll change_coin_num = change/10 + change%10;

                ll coin_num = A-i + B-j + change_coin_num;
                if(C==coin_num){
                    p(price);
                    return 0;
                }
            }
        }
    }
    p("Impossible");
    
    return 0;
}