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 (GCC 5.4.1) (judge verdict: Time Limit Exceeded)

#include <stdio.h>
#include <string.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
int acs(const void *a, const void *b){return *(int*)a - *(int*)b;} /* 1,2,3,4.. */
int des(const void *a, const void *b){return *(int*)b - *(int*)a;} /* 8,7,6,5.. */

char s[100001];
char t[100001];

int sc[26];
int tc[26];

int main(void)
{
    scanf("%s",s);
    scanf("%s",t);

    for(int i=0;s[i]!='\0';i++) sc[s[i]-'a']++;
    for(int i=0;s[i]!='\0';i++) tc[t[i]-'a']++;
    int slen = strlen(s);
    int tlen = strlen(t);

    int cmax = 0;
    for(int i=0;i<26;i++)
    {
        if( (tc[i]>0) && (sc[i] ==0) )
        {
            printf("-1\n");
            return 0;
        }
        if( tc[i]>0)
        {
            int cc = ((tc[i]-1)/sc[i] );
            cmax = cmax < cc ? cc : cmax;
        }
    }

    uint64_t ans = 0;
    int i=0;
    while(i!=tlen)
    {
        if(t[i]==s[ans%slen])
        {
            i++;
        }
        ans++;
    }
    // uint64_t ans = slen * cmax;
    // for(int i=0;i<26;i++)
    // {
    //     uint64_t a = 0;
    //     if(tc[i]>0)
    //     {
    //         if(tc[i] - (cmax * sc[i]) > 0 )
    //         {
    //             int r = tc[i] - (cmax * sc[i]);
    //             a = slen * cmax;
    //             int j = 0;
    //             while(r>0)
    //             {
    //                 a++;
    //                 if(s[j%slen]==('a'+i))
    //                 {
    //                     r--;
    //                 }
    //                 j++;
    //             }
    //         }
    //     }
    //     ans = a> ans ? a: ans;

    // }
    
    printf("%ld\n",ans);
    return 0;
}