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 Julia (0.5.0) (judge verdict: Accepted)

parseInt(x) = parse(Int, x)
parseMap(x::Array{SubString{String},1}) = map(parseInt, x)

function main()
	s = readline() |> chomp
	t = readline() |> chomp
	l = length(s)
	alf = Array{Int}(26,l)
	d = Dict{Char,Array{Int,1}}()
	for i in 1:l
		if haskey(d,s[i])
			push!(d[s[i]],i)
		else
			d[s[i]] = [i]
		end
	end
	for i in 1:26
		if haskey(d,Char(i+96))
			now = 1
			for j in 1:length(d[Char(i+96)])
				while now<d[Char(i+96)][j]
					alf[i,now] = d[Char(i+96)][j]
					now += 1
				end
			end
			while now <= l
				alf[i,now] = d[Char(i+96)][1]
				now += 1
			end
		end
	end
	k = 0
	f = 0
	z = length(t)
	now = l
	for i in 1:z
		if alf[Int(t[i])-96,now] == 0
			f = 1
			break
		elseif alf[Int(t[i])-96,now]<=now
			k += l-now+alf[Int(t[i])-96,now]
			now = alf[Int(t[i])-96,now]
		else
			k += alf[Int(t[i])-96,now]-now
			now = alf[Int(t[i])-96,now]
		end
	end
	println(f==1?-1:k)

end

main()