1228A - Distinct Digits - CodeForces Solution

def check(i):
    i = str(i)
    s = set(i)
    if len(s)==len(i):
        return 1
    else:
        return 0
    

a,b=map(int,input().split())
for i in range(a,b+1):
    if check(i)==1:
        print(i)
        exit()
print(-1)