#include <iostream>

using namespace std;

int main(){
  int a,b,c;cin>>a>>b>>c;
  int mx = min(a,b)*2;
  if(mx < c || (mx == c && a == b) || (c == 0 && mx)){
    cout << -1 << endl;
  }else if(mx == 0){
    for(int i = 0; a > i; i++)cout << "0";
    for(int i = 0; b > i; i++)cout << "1";
    cout << endl;
  }else if(mx == c){
    if(b > a){
      //10101
      for(int i = 1; c+2 > i; i++){
        cout << (i%2);
      }
      cout << endl;
    }else{
      //01010
      for(int i = 0; c+1 > i; i++){
        cout << (i%2);
      }
      cout << endl;
    }
  }else{
    int resta = a-c/2;
    int restb = b-(c+2)/2;
    for(int i = 0; resta > i; i++)cout << "0";
    for(int i = 1; c > i; i++)cout << (i%2);
    for(int i = 0; restb >= i; i++)cout << "1";
    if(c%2 == 0)cout << "0";
    cout << endl;
  }
}