#include <vector>
#include <iostream>
#include <algorithm>
#include <functional>
#include <string>
#include <math.h>
#include <map>
using namespace std;

int main(){
	int a,b,c;
	int ans=101010101;
	cin >> a >> b >> c;
	for(int k=1;k<=a+10*b;k++){
		for(int j=0;j<=b;j++){
			if(10*j-k>=10)break;
			for(int i=0;i<=a;i++){
				if(k<=i+10*j){
					int OT=i+10*j-k;
					if(c==a+b-i-j+OT || c==a+b-i-j+(OT/10)+(OT%10)){
						ans=min(ans,k);
					}
				}
			}
		}
	}
	if(ans==101010101){
		cout << "Impossible" << endl;
	}else{
		cout << ans << endl;
	}
	return 0;
}