N,M,K=map(int, input().split())
if M==0:
  if K==0:
    print('0'*N)
  else:
    print(-1)
  exit()

if N==0:
  if K==0:
    print('1'*M)
  else:
    print(-1)
  exit()
  
if K==0:
  print(-1)
  exit()
  
a,b=N,M  
A=[['0',1]]
C=[]
a-=1
for i in range(K):
  if i%2==0:
    A.append(['1',1])
    b-=1
  else:
    A.append(['0',1])
    a-=1

if a>=0 and b>=0:
  for i in range(2):
    if A[i][0]=='0':
      A[i][1]+=a 
  for i in range(2):
    if A[-1-i][0]=='1':
      A[-1-i][1]+=b 
  B=[]
  for a,b in A:
    for i in range(b):
      B.append(a)
  B=''.join(B)
  C.append(B)
  
a,b=N,M 
A=[['1',1]]
b-=1
for i in range(K):
  if i%2==0:
    A.append(['0',1])
    a-=1
  else:
    A.append(['1',1])
    b-=1

if a>=0 and b>=0:
  for i in range(2):
    if A[i][0]=='0':
      A[i][1]+=a 
  for i in range(2):
    if A[-1-i][0]=='1':
      A[-1-i][1]+=b 
  B=[]
  for a,b in A:
    for i in range(b):
      B.append(a)
  B=''.join(B)
  C.append(B)
if len(C)==0:
  print(-1)
else:
  C=sorted(C)
  print(C[0])