#include<bits/stdc++.h>
#pragma GCC optimize("Ofast")
//#pragma GCC target("avx2")
#pragma GCC optimize("unroll-loops")
using namespace std;
//#include<boost/multiprecision/cpp_int.hpp>
//#include<boost/multiprecision/cpp_dec_float.hpp>
//namespace mp=boost::multiprecision;
//#define mulint mp::cpp_int
//#define mulfloat mp::cpp_dec_float_100
struct __INIT{__INIT(){cin.tie(0);ios::sync_with_stdio(false);cout<<fixed<<setprecision(15);}} __init;
//#define INF (1<<30)
#define LINF (lint)(1LL<<56)
#define MINF (lint)(2e18)
#define endl "\n"
#define rep(i,n) for(lint (i)=0;(i)<(n);(i)++)
#define reprev(i,n) for(lint (i)=(n-1);(i)>=0;(i)--)
#define flc(x) __builtin_popcountll(x)
#define pint pair<int,int>
#define pdouble pair<double,double>
#define plint pair<lint,lint>
#define fi first
#define se second
#define all(x) x.begin(),x.end()
//#define vec vector<lint>
#define nep(x) next_permutation(all(x))
typedef long long lint;
int dx[8]={1,1,0,-1,-1,-1,0,1};
int dy[8]={0,1,1,1,0,-1,-1,-1};
const int MAX_N=3e5+5;
template<class T>bool chmax(T &a,const T &b){if(a<b){a=b;return 1;}return 0;}
template<class T>bool chmin(T &a,const T &b){if(b<a){a=b;return 1;}return 0;}
//vector<int> bucket[MAX_N/1000];
//constexpr int MOD=1000000007;
constexpr int MOD=998244353;
//typedef __int128_t llint;
//#include<atcoder/all>
//using namespace atcoder;

int main(void){
    int N,M,K;
    cin >> N >> M >> K;
    if(K==0){
        if(N!=0 && M!=0) cout << -1 << endl;
        else if(N==0){
            rep(i,M) cout << 1;
            cout << endl;
        }
        else{
            rep(i,N) cout << 0;
            cout << endl;
        }
        return 0;
    }
    string ans1="2",ans2="2";
    if(N>=K/2+1 && M>=(K+1)/2){
        int n=K/2+1,m=(K+1)/2;
        vector<string> zeros(n),ones(m);
        rep(i,n) zeros[i]="0";
        rep(i,N-n) zeros[0]+="0";
        rep(i,m) ones[i]="1";
        rep(i,M-m) ones[m-1]+="1";
        ans1.clear();
        rep(i,K+1){
            if(i%2==0) ans1+=zeros[i/2];
            else ans1+=ones[i/2];
        }
    }
    if(N>=(K+1)/2 && M>=K/2+1){
        int m=K/2+1,n=(K+1)/2;
        vector<string> zeros(n),ones(m);
        rep(i,n) zeros[i]="0";
        rep(i,N-n) zeros[0]+="0";
        rep(i,m) ones[i]="1";
        rep(i,M-m) ones[m-1]+="1";
        ans2.clear();
        rep(i,K+1){
            if(i%2==0) ans2+=ones[i/2];
            else ans2+=zeros[i/2];
        }
    }
    if(min(ans1,ans2)=="2") cout << -1 << endl;
    else cout << min(ans1,ans2) << endl;
}