N, M, K = map(int, input().split())
if N == 0:
    if K == 0:
        print("1"*M)
    else:
        print(-1)
    exit()
elif M == 0:
    if K == 0:
        print("0"*N)
    else:
        print(-1)
    exit()
    
if N == 1:
    if M == 1:
        if K == 1:
            print("01")
        else:
            print(-1)
    else:
        if K == 1:
            print("0" + "1" * M)
        elif K == 2:
            print("10" + "1" * (M - 1) )
        else:
            print(-1)
    exit()
    
if M == 1:
    if K == 1:
        print("0" * N + "1")
    elif K == 2:
        print("0" * (N - 1) + "10")
    else:
        print(-1)
    exit()
    
if K == 0:
    print(-1)
    exit()

minv = min(N, M)
if K > minv * 2:
    print(-1)
    exit()
elif K == minv * 2:
    if N == M:
        print(-1)
    elif N > M:
        s = "0" * (N - minv - 1) + "01" * minv + "0"
        print(s)
    else:
        s = "1" + "01" * minv + "1" * (M - minv - 1)
        print(s)
    exit()
else:
    if K % 2:
        n = (K + 1)//2
        s = "0" * (N - n) + "01" * (n) + "1" * (M - n)
        print(s)
    else:
        n = K//2
        s = "0" * (N - n - 1) + "01" * n + "1" + (M - n) + "0"
        print(s)