#include <iostream>
#include <string>
#include <vector>
#include <map>
#include <utility>
#include <set>
#include <queue>
#include <deque>
#include <algorithm>
using namespace std;

int main() {
	int A, B, C;
	cin >> A >> B >> C;
	if(A+B<=C) cout << "Impossible" << endl;
	else{
	    if(B>=C) cout << A+10*(B-C) << endl;
	    else{
	        int m, n;
	        m=n=A-(C-B);
	        while(m-9>0 && n+1<=A){
	            m -= 9;
	            ++n;
	        }
	        cout << m << endl;
	    }
	}
	return 0;
}