sdvig_strok

s=input()
s1=input()
step = int()
if s==s1:
    print(0)
elif len(s) == len(s1):
    while s!= s1 and step != len(s1):
        step+=1
        s = s[-1:]+s[:-1]
    if step !=len(s):
        print(step)
    else:
        print(-1)
else:
    print(-1)