import sys
input = sys.stdin.readline
mod = 998244353

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

if K == 0:
    print(-1)
    exit()
if N == M:
    if K > N + M - 1:
        print(-1)
        exit()
else:
    if K > min(N, M) * 2:
        print(-1)
        exit()

if K & 1:
    x = K // 2
    S = ["0" * (N - x)]
    for _ in range(x):
        S.append("1")
        S.append("0")
    S.append("1" * (M - x))
    print("".join(S))
else:
    if K == min(N, M) * 2 and M > N:
        x = K // 2
        print("10" * x + "1" * (M - N))
    else:
        x = K // 2
        S = ["0" * (N - x)]
        for _ in range(x):
            S.append("1")
            S.append("0")
        S.pop()
        for _ in range(M - x):
            S.append("1")
        S.append("0")
        print("".join(S))