N,M,K=map(int,input().split())
ans_lst=[2]
for a in range(2):
    A=[(a+k)%2 for k in range(K+1)]
    cnt0=A.count(0)
    cnt1=A.count(1)
    if cnt0<=N and cnt1<=M:
        C=[[1]*(cnt0-1)+[N-(cnt0-1)],[M-(cnt1-1)]+[1]*(cnt1-1)]
        B=[]
        for a in A:
            B+=[a]*C[a].pop()
        ans_lst=min(ans_lst,B)
if ans_lst[0]==2:
    print(-1)
else:
    print(*ans_lst,sep="")