import std.conv, std.functional, std.range, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.bitmanip, std.complex, std.container, std.math, std.mathspecial, std.numeric, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }


string solve(int A, int B, int K) {
  auto ans = new char[A + B];
  ans[] = '?';
  
  if (A == 0) {
    if (K == 0) {
      ans[] = '0';
      return ans.to!string;
    }
    return "-1";
  }
  if (B == 0) {
    if (K == 0) {
      ans[] = '1';
      return ans.to!string;
    }
    return "-1";
  }
  
  if (K == 0) {
    return "-1";
  }
  if (K > min(2 * A, 2 * B, A + B - 1)) {
    return "-1";
  }
  
  foreach_reverse (a; 0 .. A + 1) {
    // 0^a (10)^c 1^b 0^d
    foreach (d; 0 .. 2) {
      const c = A - a - d;
      const b = B - c;
      if (c >= 0 && b >= 0) {
        int k;
        if (c == 0) {
          if (a > 0 && b > 0) k += 1;
        } else {
          if (a > 0) k += 1;
          k += (2 * c - 1);
          if (b > 0) k += 1;
        }
        if (b > 0 && d > 0) k += 1;
        if (k == K) {
          ans[] = '0';
          foreach (i; 0 .. c) ans[a + 2 * i] = '1';
          ans[a + 2 * c .. $] = '1';
          return ans.to!string;
        }
      }
    }
  }
  assert(false, format("HELP %s %s %s", A, B, K));
}

void main() {
  debug {
    foreach (a; 0 .. 10 + 1) foreach (b; 0 .. 10 + 1) foreach (k; 0 .. 20 + 1) {
      const res = solve(a, b, k);
      writeln(a, " ", b, " ", k, ": ", res);
    }
  }
  
  try {
    for (; ; ) {
      const A = readInt;
      const B = readInt;
      const K = readInt;
      
      const ans = solve(A, B, K);
      writeln(ans);
    }
  } catch (EOFException e) {
  }
}