#include<bits/stdc++.h>
using namespace std;
using Int = long long;
template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}

//INSERT ABOVE HERE
Int pay(Int i,Int j,Int k){
  Int x=(i+j*10)-k;
  return (x/10)+(x%10);
}
signed main(){
  Int a,b,c;
  cin>>a>>b>>c;
  Int ans=1e9;  
  for(Int i=0;i<=a;i++){
    for(Int j=0;j<=b;j++){
      for(Int k=1;k<=i+j*10;k++){
        Int x=pay(i,j,k)+(a-i)+(b-j);
        if(x==c) chmin(ans,k);
      }
    }
  }  
  auto NG=[](){cout<<"Impossible"<<endl;exit(0);};
  if(ans>a+10*b) NG();
  cout<<ans<<endl;
  return 0;
}