s = input()
t = input()
num = s.count(t)
if len(t) == 1 and num > 0:
    print(-1)
    exit()

tidx = 0
sidx = 0
ans = 0
for i in range(len(s)*2):
    if sidx >= len(s):
        break
    if s[sidx] == t[tidx]:
        if tidx == len(t)-1:
            ans += 1
            tidx = 0
        else:
            tidx += 1
            sidx += 1
    else:
        tidx = 0
        sidx += 1

print(ans)