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 Fortran (gfortran v4.8.4) (judge verdict: Wrong Answer)

program main
  implicit none
  integer(8) i,ns,nt,judge,ans,j,c2
  character(10**5) s,t
  character c1
  read(*, *)s, t
  ns = len(trim(s))
  nt = len(trim(t))
  ans = 1
  c2 = 1
  judge = 1
  do i = 1,nt
    c1 = t(i:i)
    do j = 1,ns+1
      ans = ans + 1
      c2 = c2 + 1
      if (c2 == ns + 1) then
        c2 = 1
      end if 
      if (j == ns + 1) then
        judge = 0
        exit
      elseif (s(c2:c2) == c1) then
        exit
      end if
    end do
    if (judge == 0) then
      exit
    end if
  end do
  !read(*, *) (L(i), i = 1,N)
  if (judge == 0) then
    write(*, *) -1
  else
    write(*, *) ans
  end if
end program main