# #    ⋀_⋀  #   (・ω・) # ./ U ∽ U\ # │* 合 *│ # │* 格 *│ # │* 祈 *│ # │* 願 *│ # │*   *│ #  ̄ # import sys sys.setrecursionlimit(10**6) input=sys.stdin.readline from math import floor,sqrt,factorial,hypot,log #log2ないyp from heapq import heappop, heappush, heappushpop from collections import Counter,defaultdict,deque from itertools import accumulate,permutations,combinations,product,combinations_with_replacement from bisect import bisect_left,bisect_right from copy import deepcopy from fractions import gcd from random import randint def ceil(a,b): return (a+b-1)//b inf=float('inf') mod = 10**9+7 def pprint(*A): for a in A: print(*a,sep='\n') def INT_(n): return int(n)-1 def MI(): return map(int,input().split()) def MF(): return map(float, input().split()) def MI_(): return map(INT_,input().split()) def LI(): return list(MI()) def LI_(): return [int(x) - 1 for x in input().split()] def LF(): return list(MF()) def LIN(n:int): return [I() for _ in range(n)] def LLIN(n: int): return [LI() for _ in range(n)] def LLIN_(n: int): return [LI_() for _ in range(n)] def LLI(): return [list(map(int, l.split() )) for l in input()] def I(): return int(input()) def F(): return float(input()) def ST(): return input().replace('\n', '') def main(): S=ST() T=ST() if len(T)==1 and S.count(T): print(-1) return ans = 0 N=len(S) i = 0 while i2: i+=len(T)-1 else: i+=1 print(ans) if __name__ == '__main__': main()