n,m,k = map(int,input().split())


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)