#include<iostream>
#include<map>
#include<vector>
#include <algorithm>
#include<math.h>
#include <iomanip>
#include<set>
#include <numeric>
using namespace std;


int main()
{
    int a, b, c, r;
    cin >> a >> b >> c;
    r = a + b;
    if (r > c && b >= c) cout << a + (b-c)*10 << endl;
    else if (r > c && b < c && a <= 9) cout << r - c << endl;
    else if (r > c && b < c && a > 9){
        if ((r - c) >= 10) cout << r - c - 9 << endl;
        else cout << r - c << endl;
    }
    else if (r == c && b > 0) cout << 9 << endl; 
    else if (r < c && b < c && b > 0 && c - r < 9) cout << 9 - (c - r) << endl;
    else if (r <= c && c - a - b <= 9 && b > 0 && b < 10) cout << 9 - c + b + a << endl;
    else cout << "Impossible" << endl;
}