#include <bits/stdc++.h>
using ll = long long;
#define MOD 1000000007
#define Mod 998244353
const int MAX = 1000000005;
const long long INF = 1000000000000000005LL;
using namespace std;

int main() {
    int n, m, k;
    cin >> n >> m >> k;
    string ans;
    if (k%2) {
        if (n < (k+1)/2 or m < (k+1)/2) {
            cout << -1 << endl;
            return 0;
        }
        n -= (k+1)/2; m -= (k+1)/2;
        for (int i = 0; i < n; i++) ans.push_back('0');
        for (int i = 0; i < k+1; i++) {
            if (i%2) ans.push_back('1');
            else ans.push_back('0');
        }
    } else {
        if (n >= (k+2)/2 and m == k/2) {
            n -= (k+2)/2;
            for (int i = 0; i < n; i++) ans.push_back('0');
            for (int i = 0; i < k+1; i++) {
                if (i%2) ans.push_back('1');
                else ans.push_back('0');
            }
        } else if (n == k/2 and m >= (k+2)/n) {
            m -= (k+2)/2;
            for (int i = 0; i < k+1; i++) {
                if (i%2) ans.push_back('0');
                else ans.push_back('1');
            }
            for (int i = 0; i < m; i++) ans.push_back('1');
        } else {
            cout << -1 << endl;
            return 0;
        }
    }
    cout << ans << endl;
}