Problem:
Score : 500 points

Problem Statement

Given are two strings s and t consisting of lowercase English letters. Determine if there exists an integer i satisfying the following condition, and find the minimum such i if it exists.

Let s' be the concatenation of 10^{100} copies of s. t is a subsequence of the string {s'}_1{s'}_2\ldots{s'}_i (the first i characters in s').

Notes

A subsequence of a string a is a string obtained by deleting zero or more characters from a and concatenating the remaining characters without changing the relative order. For example, the subsequences of contest include net, c, and contest.

Constraints

1 \leq |s| \leq 10^5

1 \leq |t| \leq 10^5

s and t consists of lowercase English letters.

Input

Input is given from Standard Input in the following format:

s
t

Output

If there exists an integer i satisfying the following condition, print the minimum such i; otherwise, print -1.

Sample Input 1

contest
son

Sample Output 1

10

t = son is a subsequence of the string contestcon (the first 10 characters in s' = contestcontestcontest...), so i = 10 satisfies the condition.

On the other hand, t is not a subsequence of the string contestco (the first 9 characters in s'), so i = 9 does not satisfy the condition.

Similarly, any integer less than 9 does not satisfy the condition, either. Thus, the minimum integer i satisfying the condition is 10.

Sample Input 2

contest
programming

Sample Output 2

-1

t = programming is not a substring of s' = contestcontestcontest.... Thus, there is no integer i satisfying the condition.

Sample Input 3

contest
sentence

Sample Output 3

33

Note that the answer may not fit into a 32-bit integer type, though we cannot put such a case here.

Solution in Python (3.4.3) (judge verdict: Wrong Answer)

#coding: utf-8
s = str(input())
t = str(input())
ans = 0
ans1 = 0
# s.sort(reversed=True)
# t.sort(reversed=True)
flg = 0

for i in range(len(t)):
	for j in range(ans1,len(s)):
		if t[i] == s[j]:
			flg = 1
			# if j > ans1:
			# print('jが大きい'+str(j))
			# ans = ans - ans1 + j + 1
			ans1 = j
			# else:
			# 	print('jが小さい'+str(j))
			# 	ans = ans + len(s)
			# 	ans1 = j
			break
		# elif t[i] < s[j]:
		# 	flg = 0
		# 	break
	if flg == 0:
		for j in range(0,ans1):
			if t[i] == s[j]:
				flg = 1
				# print('jが小さい'+str(j))
				ans = ans + len(s)
				ans1 = j
				
	if flg == 0:
		ans = -1
		break
	else:
		# ans = ans + ans1
		flg = 0
		# ans1 = 0

if ans == -1:
	print(-1)
else:
	print(ans+ans1+1)