#include <bits/stdc++.h>
using namespace std;

int main() {
  int64_t N, M, K;
  cin >> N >> M >> K;
  if (N < M && K > 2 * N) {
      cout << -1 << endl;
  }
  else if (N == M && K >= 2 * N) {
      cout << -1 << endl;
  }
  else if (N > M && K > 2 * M) {
      cout << -1 << endl;
  }
  else if (K / 2 * 2 == K) {
      if (K == 0) {
if (M == 0) {
for (int p = 0; p < N; p++) {
cout << 0;
}
}
else if (N == 0) {
for (int p = 0; p < M; p++) {
cout << 1;
}
}
else {
cout << -1 << endl;
}
  }
else {
for (int i = 0; i < N - K / 2; i++) {
cout << 0;
}
for (int i = 0; i < (K - 2) / 2; i++) {
cout << 10;
}
for (int i = 0; i < M - (K - 2) / 2; i++) {
cout << 1;
}
cout << 0;
}
}
else if (K / 2 * 2 != K) {
for (int j = 0; j < N - (K - 1) / 2; j++) {
cout << 0;
}
for (int j = 0; j < (K - 1) / 2; j++) {
cout << 10 << endl;
}
for (int j = 0; j < M - (K - 1) / 2; j++) {
cout << 1 << endl;
}
}
}