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: Runtime Error)

#include<bits/stdc++.h>

using namespace std;

#define ll long long
#define ii pair<int ,int>
#define iii tuple<int ,int, int>
#define vi vector<int>
#define vii vector<int, int>
#define fo(i,a,n) for(int i = (a); i < (n); i++)
#define pb push_back
#define newl cout<<"\n"
#define mp make_pair
#define mt make_tuple
#define f first
#define s second
#define N1 100000

//int visited[N1]={};
//int st[4*N1 + 10]={};
const ll MAXN=1e+5+7;
char s[MAXN], t[MAXN];
ll run_s=0, run_t=0, co=0;
ll ns, nt, f=1;

int main(){
	cin>>s>>t;
	ns=strlen(s); nt=strlen(t);

	fo(i,0,nt){
		while(t[i]!=s[run_s]){
			//cout<<run_s<<" ";
			if(run_s==ns-1) run_s=0;
			else run_s++;
			co++;
			if(co==ns+1) {
				f=0;
				break;
			}
		}
		run_s++;
		//cout<<co<<" ";
		if(co==ns+1) {
			f=0;
			break;
		}
	}

	if(f) cout<<co+nt;
	else cout<<-1;

}