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

print(ans)
#if ans != -1:
#    print(len(ans),ans.count("0"),ans.count("1"))