N,M,K=map(int,input().split())
def cnt(a,N,M):
  if N==0 or M==0: return 0
  elif a==0: return 1
  else: return 2*a-1+(1 if M>a else 0)+(1 if N>a else 0)
ans=-1
for i in range(min(N,M)+1):
  if cnt(i,N,M)==K: ans=i; break
if K==2 and N>1: print('0'*(N-1)+'1'*M+'0')
elif ans==-1: print(ans)
else: print('0'*(N-ans)+'10'*ans+'1'*(M-ans))