#include<bits/stdc++.h>

#define unless(x) if (!(x))
#define pb push_back
#define eb emplace_back
/* #define f first */
/* #define s second */
#define lb lower_bound
#define ub upper_bound
#define ins insert
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define mem(x, y) memset(x, y, sizeof(x))
#define sz(x) ((int) (x).size())
#define popcount __builtin_popcountll

using namespace std;
using ll = long long;
using ld = long double;
using pi = pair<int, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vll = vector<ll>;
using vpi = vector<pi>;
using vpll = vector<pll>;
using vvi = vector<vector<int>>;
using vvll = vector<vector<ll>>;
template<typename T> using minpq = priority_queue<T, vector<T>, greater<T>>;
template<typename T> using maxpq = priority_queue<T, vector<T>, less<T>>;

// *INDENT-OFF*
template<class T> bool ckmin(T& a, const T& b) { return b < a ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }
void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\'' << x << '\''; }
void __print(const char *x) { cerr << '\"' << x << '\"'; }
void __print(const string &x) { cerr << '\"' << x << '\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }
template<typename T, typename V> void __print(const pair<T, V> &x) { cerr << '{'; __print(x.first); cerr << ", "; __print(x.second); cerr << '}'; }
template<size_t I = 0, typename... Tp> void __print_tup(const tuple<Tp...>& t) { cerr << get<I>(t); if constexpr(I < sizeof...(Tp) - 1) { cerr << ", "; __print_tup<I+1>(t); } }
template<typename... Tp> void __print(const tuple<Tp...>& t) { cerr << '{'; __print_tup(t); cerr << '}'; }
template<typename T> void __print(const T &x) { int f = 0; cerr << '{'; for (auto &i : x) cerr << (f++ ? ", " : ""), __print(i); cerr << "}"; }
void _print() { cerr << "]\n"; }
template <typename T, typename... V> void _print(T t, V... v) { __print(t); if (sizeof...(v)) cerr << ", "; _print(v...); }
template<typename T> T fdiv(T x, T y) { T q = x / y; T r = x % y; if ((r != 0) && ((r < 0) != (y < 0))) --q; return q; }
template<typename T> T cdiv(T x, T y) { return x / y + ((x % y != 0) ? !((x > 0) ^ (y > 0)) : 0); }
namespace std { template<class Fun> class y_combinator_result { Fun fun_; public: template<class T> explicit y_combinator_result(T &&fun): fun_(std::forward<T>(fun)) {} template<class ...Args> decltype(auto) operator()(Args &&...args) { return fun_(std::ref(*this), std::forward<Args>(args)...); } }; template<class Fun> decltype(auto) yy(Fun &&fun) { return y_combinator_result<std::decay_t<Fun>>(std::forward<Fun>(fun)); } }
template<typename T1, typename T2> /* cin >> pair<T1, T2> */ istream& operator>>(istream &istream, pair<T1, T2> &p) { return (istream >> p.first >> p.second); }
template<typename T> /* cin >> vector<T> */ istream& operator>>(istream &istream, vector<T> &v) { for (auto &it : v) cin >> it; return istream; }
template<typename T1, typename T2> /* cout << pair<T1, T2> */ ostream& operator<<(ostream &ostream, const pair<T1, T2> &p) { return (ostream << p.first << " " << p.second); }
template<typename T> /* cout << vector<T> */ ostream& operator<<(ostream &ostream, const vector<T> &c) { for (auto &it : c) cout << it << " "; return ostream; }
ll sum_n(int n) { return (ll) n * (n + 1) / 2; }
const string yes = "Yes";
const string no = "No";
#ifdef LOCAL
#define dbg(x...) cerr << "\e[1;31m"<<__func__<<":"<<__LINE__<<" [" << #x << "] = ["; _print(x); cerr << "\e[0m";
#else
#define dbg(x...)
#endif
// *INDENT-ON*

// YOU ARE ACTUALLY **SUPPOSED** TO READ THE FOLLOWING.
// No need to hurry. Relax.
// Read Problems Carefully. (Please do this, you keep making mistakes because you avoided this.)
// Read both the input sizes (i.e. n <= 1e5, etc) and the sum of n thing. (i.e. sum of n <= 1e6, etc).
// Be Careful about input data size. You keep inputting data as int, when long long was required.
// Don't force some technique on a problem. BS does not solve everything. On many occasions, greedy rules.
// Declare double values as long double or ld (NEVER double, because of precision issues)

void solve() {
    int n, m, k;
    cin >> n >> m >> k;
    if (n == 0) {
        if (k == 0) {
            cout << string(m, '1') << '\n';
        } else {
            cout << -1 << '\n';
        }
    } else if (m == 0) {
        if (k == 0) {
            cout << string(n, '0') << '\n';
        } else {
            cout << -1 << '\n';
        }
    } else {
        if (n == m && k > 2 * n - 1) {
            cout << -1 << '\n';
        } else if (n != m && k > 2 * min(n, m)) {
            cout << -1 << '\n';
        } else {
            string ans;
            for (int i = 0; i < cdiv(k, 2); i++) {
                ans += "01";
            }
            n -= cdiv(k, 2);
            m -= cdiv(k, 2);
            string f = string(n, '0');
            string b = string(m, '1');
            if (k % 2 == 0) {
                if (n == 0) {
                    f += char('1');
                    b.pop_back();
                } else {
                    b += char('0');
                    f.pop_back();
                }
            }
            cout << f << ans << b << '\n';
        }
    }
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int t = 1;
    /* cin >> t; */
    while (t--) {
        solve();
    }
    return 0;
}