def partial_match_table(word):
    table = [0] * (len(word) + 1)
    table[0] = -1
    i, j = 0, 1
    while j < len(word):
        matched = word[i] == word[j]
        if not matched and i > 0:
            i = table[i]
        else:
            if matched:
                i += 1
            j += 1
            table[j] = i
    return table

def kmp_search(text, word):
    table = partial_match_table(word)
    i, p = 0, 0
    results = []
    while i < len(text) and p < len(word):
        if text[i] == word[p]:
            i += 1
            p += 1
            if p == len(word):
                p = table[p]
                results.append((i-len(word), i))
        elif p == 0:
            i += 1
        else:
            p = table[p]
    return results

s = input().strip()
t = input().strip()
if len(t) == 1 and t in s:
    import sys
    print(-1)
    sys.exit()
rs = []
for i, (a, b) in enumerate(kmp_search(s, t)):
#    print(a,b-1)
    rs.append((a, 1, i))
    rs.append((b-1, 0, i))
rs.sort()
r = 0
ts = set()
for x, f, i in rs:
    if f == 1:
        ts.add(i)
        continue
    if f == 0 and i in ts:
        ts = set()
        r += 1
        continue
print(r)