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 (Clang 3.8.0) (judge verdict: Wrong Answer)

#include<stdio.h>
#include<string.h>

int main(void){
  char a[100001];
  char b[100001];
  char c[100001];
  int i;
  int j;
  int cnt = 0;
  int len1;
  int len2;
  int f = 0;
  
  scanf("%c", a);
  scanf("%c", b);
  
  len1 = strlen(b);
  len2 = strlen(a);
  
  for(i = 0; i < 10; i++){
    strcat(a, b);
  }
  
  for(i = 0; i < len1; i++){
    for (j = 0; j < len2; j++){
      if(a[j] == b[i]){
        f = 114514;        
      }
    }
  }
  i = 0;
  j = 0;
  while(len1 == 0){
    if(a[i] == b[j]){
      len1--;
      j++;
      cnt += i + 1;
    }else{
      i++;
    }
  }
      
    
        
        
        
        
        
        
     if(f == 0){
       printf("-1");
     }else{
       printf("%d", cnt);
     }
     return 0;
}