#include <iostream>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <iomanip>
#include <queue>
#include <algorithm>
#include <numeric>
#include <deque>
#include <complex>
#include <cassert>

using namespace std;
using ll = long long;

int main(){

    ll N, M, K;
    cin >> N >> M >> K;
    if (N < K/2+1 || M < (K+1)/2){
        cout << -1 << endl;
        return 0;
    }

    for (int i=0; i<N-(K/2+1); i++) cout << 0;
    for (int i=0; i<K+1; i++){
        if (i % 2 == 0) cout << 0;
        else cout << 1;
    }
    for (int i=0; i<M-(K+1)/2; i++) cout << 1;
    cout << endl;

    return 0;
}