#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
//using mint = static_modint<998244353>;
//using mint = modint;
using mint = static_modint<1000000007>;
using vm = vector<mint>;
using vvm = vector<vm>;
ostream &operator<<(ostream &o,const mint &m){cout<<m.val();return o;}
using ll = long long;
using vl = vector<ll>;
using vvl = vector<vl>;
using pl = pair<ll,ll>;
#define rep(i,n) for(ll i=0;i<(ll)(n);++i)
#define reps(i,s,n) for(ll i=(s);i<(ll)(n);++i)
#define rep1(i,n) for(ll i=1;i<=(ll)(n);++i)
#define ts(i) to_string(i)
#define chmin(x,y) x=min(x,y)
#define chmax(x,y) x=max(x,y)
const long long INF = 1e18;

#ifdef DEBUG
#include <debug.hpp>
#endif
string solve(){
	ll N,M,K;
	cin >> N>>M>>K;

#ifdef DEBUG
	cout<<"N="<<N<<" M="<<M<<" K="<<K<<endl;
#endif
	string s="";
	if(K==0){
		if(N>0&&M>0) return "-1";
		if(N>0){
			rep(i,N)s+='0';
		}else{
			rep(i,M)s+='1';
		}
		return s;
	}
	string v0="",v1="";
	ll a,b;
	if(K%2){
		a=(K+1)/2;b=(K+1)/2;
	}else{
		a=K/2+1;b=K/2;
	}
#ifdef DEBUG
	cout<<"a="<<a<<" b="<<b<<endl;
#endif
	if(a>N||b>M)return "-1"; //N,M short
	rep(i,N-a){
		v0+='0';
	}
	rep(i,K+1){
		if(i%2)v0+='1';
		else v0+='0';
	}
	v1='1';
	rep(i,N-a){
		v1+='0';
	}
	rep(i,K-1){
		if(i%2)v1+='1';
		else v1+='0';
	}
	if(v0>v1)s=v1;
	else s=v0;
	return s;
}

int main(){
#ifdef DEBUG
	cout << "--- Input ---" << endl;
#endif
#ifdef DEBUG
	cout << "--- Answer ---" << endl;
#endif
	cout<<solve()<<endl;
}
//cout << fixed << setprecision(9);