import sys, math
input = lambda: sys.stdin.readline()[:-1]
def MI(): return map(int, input().split())
inf = 10**18

n,m,k = MI()

if n==0:
    if k==0:
        print('1'*m)
    else:
        print(-1)
    exit()
if m==0:
    if k==0:
        print('0'*n)
    else:
        print(-1)
    exit()

cnt = [0,0]
ans = []
for i in range(k+1):
    cnt[i%2] += 1
    ans.append(str(i%2))
# print(ans)
# print(cnt)
if cnt[0] > n or cnt[1] > m:
    print(-1); exit()

ans[0] += '0'*(n-cnt[0])
if (k+1)%2==0:
    ans[-1] += '1'*(m-cnt[1])
else:
    ans[-2] += '1'*(m-cnt[1])
print("".join(ans))