n,m,k = map(int,input().split()) if n*m == 0: if k: print(-1) else: print("0"*n+"1"*m) exit() need = k//2 zero = need one = need if k%2 == 0: zero += 1 one = need if n < zero or m < one: print(-1) exit() ans = "0"*(n-zero) + "01"*need ans += "1"*(m-one) if k%2 == 0: ans += "0" print(ans)