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 C++14 (GCC 5.4.1) (judge verdict: Time Limit Exceeded)

#include "bits/stdc++.h"
#define ll long long
#define ALL(x) x.begin(),x.end()
#define MOD 1000000007
using namespace std;

int main(){
string s,t;
cin>>s>>t;
ll tmp;
ll cou=0;
ll tty=0;
ll p=0;
ll f;
ll last;
for(int i=0;i<t.size();i++){
f=0;
for(int j=p;j<s.size();j++){
if(t[i]==s[j]){
f=1;
p=j+1;
last=j;
break;
}
}



if(f==1){
  continue;
}
cou++;

for(int j=0;j<s.size();j++){
if(t[i]==s[j]){
f=1;
p=j+1;
last=j;
break;
}
}




if(f==0){
  cout<<-1<<endl;
  return 0;
}
}
cout<<cou*s.size()+last+1<<endl;
}