#include <stdio.h>
#include <iostream>
#include <vector>
#include <queue>
#include <stack>
#include <algorithm>

#pragma GCC optimize("O2")

using ll = long long int;
const int INF = (1<<30);
const ll INFLL = (1ll<<60);
const ll MOD = (ll)(1e9+7);

#define l_ength size

void mul_mod(ll& a, ll b){
	a *= b;
	a %= MOD;
}

void add_mod(ll& a, ll b){
	a = (a<MOD)?a:(a-MOD);
	b = (b<MOD)?b:(b-MOD);
	a += b;
	a = (a<MOD)?a:(a-MOD);
}

int z[2][100100];

int main(void){
	int n,m,k,a,b,i,j,l;
	std::cin >> n >> m >> k; ++k;
	a = (k+1)/2; b = k/2;
	if(n >= a && m >= b){
		n -= a; m -= b;
		for(i=0; i<a; ++i){
			++z[0][i];
		}
		for(i=0; i<b; ++i){
			++z[1][i];
		}
		z[0][0] += n; z[1][b-1] += m;
	}else if(n >= b && m >= a){
		n -= b; m -= a;
		for(i=1; i<=b; ++i){
			++z[0][i];
		}
		for(i=0; i<a; ++i){
			++z[1][i];
		}
		z[0][0] += n; z[1][a-1] += m;
	}else{
		std::cout << "-1" << std::endl;
		return 0;
	}
	for(i=0; i<k; ++i){
		for(j=0; j<2; ++j){
			for(l=0; l<z[j][i]; ++l){
				std::cout << j;
			}
		}
	}
	std::cout << std::endl;
	return 0;
}