N, M, K = map(int, input().split())
a = min(N, M)
b = max(N, M)
if a == b and 2 * a - 1 < K:
    print(-1)
    exit()
if a != b and 2 * a < K:
    print(-1)
    exit()
if N <= M and 2 * N == K:
    print("10" * N + "1" * (M - N))
    exit()
if N >= M and 2 * M == K:
    print("0" * (N - M) + "10" * (M))
    exit()
if K % 2 == 0:
    print("0" * (N - K // 2) + "10" * (K // 2 - 1) + "1" * (M - K // 2 + 1) + "0")
    exit()
else:
    print("0" * (N - (2 * K - 1) // 2) + "01" * ((2 * K - 1) // 2) + "1" * (M - (2 * K - 1) // 2))