n,m,k = map(int,input().split())
if k%2:
  t = (k+1)//2
  if n < t or m < t:
    ans = -1
  else:
    ans = "0"*(n-t)+"01"*t+"1"*(m-t)
else:
  t = k//2
  if n >= t+1 and m >= t:
    ans = "0"*(n-t)+"10"*t+"1"*(m-t)
  elif n >= t and m >= t+1:
    ans = "1"+"0"*(n-t)+"01"*t+"1"*(m-t-1)
  else:
    ans = -1
print(ans)