#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0;i<n;i++)
typedef long long ll;
#define int long long
static const int mod=1000000007;

signed main(){
  int a,b,c;
  cin>>a>>b>>c;
  int temp=a/10;
  b+=temp;
  a-=temp*10;
  //cout<<a<<" "<<b<<endl;
  int minans=1000000007;
  for(int i=0;i<=a+10*b;i++){
    for(int j=0;j<=a;j++){
      for(int k=0;k<=b;k++){
        if(j+k*10==i && a-j+b-k==c){
          //cout<<"#"<<i<<endl;
          minans=min(minans,i);
        }
        if(j+k*10>=i && j+k*10-i+a-j+b-k==c){
          //cout<<j<<" "<<k<<"$"<<i<<endl;
          minans=min(minans,i);
        }
      }
    }
  }
  if(minans==0){
    cout<<"Impossible"<<endl;
    return 0;
  }
  cout<<minans<<endl;
  return 0;
}