import math
N,M,K=map(int,input().split())

if K%2==1:
    n=(K+1)//2
    if N-n+1<=0 or M-n+1<=0 or n<1:
        print(-1)
    else:
        ans="0"*(N-n+1)+"10"*(n-1)+"1"*(M-n+1)
        print(ans)
elif K==0:
    if N==0:
        print("1"*M)
    elif M==0:
        print("0"*N)
    else:
        print(-1)
else:
    n=K//2
    if N-n<=0 or n-1<0 or M-n+1<=0:
        print(-1)
    else:
        ans="0"*(N-n)+"10"*(n-1)+"1"*(M-n+1)+"0"
        print(ans)