#include <iostream>
#define rep(i,n) for(int i = 0;i<n;i++)
#define all(x) x.begin(),x.end() 
#define yesif(x) cout << ((x) ? "Yes": "No") << endl 
using namespace std;

int main() {
    int n,m,k;cin>>n>>m>>k;
    if(n+m-1-k >= 0){
        cout << string(n+m-1-k,'0') ;
        rep(i,k) cout << "01";
        cout << endl;
    } else {
        cout << -1 << endl;
    }
}