n,m,k=map(int,input().split())
d=min(n,m)*2
if n!=m:
    d-=1
if d<k:
    print(-1)
    exit()

def f(n,m,k):
    if n==0:
        return ""
    s="0"
    n-=1
    for i in range(k):
        if ~i&1:
            if m==0:
                return ""
            else:
                s+="1"
        else:
            if n==0:
                return ""
            else:
                s+="0"
    return s
    
s=f(n,m,k)
if not s:
    s=f(m,n,k)
    s=s.replace("1","x").replace("0","1").replace("x","0")
n-=s.count("0")
m-=s.count("1")
if n:
    for i in range(len(s)):
        if s[i]=="0":
            s=s[:i]+"0"*(n+1)+s[i+1:]
            break
if m:
    for i in range(len(s))[::-1]:
        if s[i]=="1":
            s=s[:i]+"1"*(m+1)+s[i+1:]
            break
print(s)