codeforces 1015B

B. Obtaining the String

time limit per test

1 second

memory limit per test

256 megabytes

input

standard input

output

standard output

You are given two strings $\mathrm{ss and tt.\; Both\; strings\; have\; length nn and\; consist\; of\; lowercase\; Latin\; letters.\; The\; characters\; in\; the\; strings\; are\; numbered\; from 11 to nn.}$

You can successively perform the following move any number of times (possibly, zero):

• swap any two adjacent (neighboring) characters of $\mathrm{ss (i.e.\; for\; any i=\{1,2,\dots ,n-1\}i=\{1,2,\dots ,n-1\} you\; can\; swap sisi and si+1)si+1).}$

You can't apply a move to the string $\mathrm{tt.\; The\; moves\; are\; applied\; to\; the\; string ss one\; after\; another.}$

Your task is to obtain the string $\mathrm{tt from\; the\; string ss.\; Find\; any\; way\; to\; do\; it\; with\; at\; most 104104 such\; moves.}$

You do not have to minimize the number of moves, just find any sequence of moves of length ${\mathrm{104104 or\; less\; to\; transform ss into tt.}}^{}$

Input

The first line of the input contains one integer $\mathrm{nn (1\le n\le 501\le n\le 50)\; —\; the\; length\; of\; strings ss and tt.}$

The second line of the input contains the string $\mathrm{ss consisting\; of nn lowercase\; Latin\; letters.}$

The third line of the input contains the string $\mathrm{tt consisting\; of nn lowercase\; Latin\; letters.}$

Output

If it is impossible to obtain the string $\mathrm{tt using\; moves,\; print\; "-1".}$

Otherwise in the first line print one integer $\mathrm{kk —\; the\; number\; of\; moves\; to\; transform ss to tt.\; Note\; that kk must\; be\; an\; integer\; number\; between 00and 104104 inclusive.}$

In the second line print $\mathrm{kk integers cjcj (1\le cj<n1\le cj<n),\; where cjcj means\; that\; on\; the jj-th\; move\; you\; swap\; characters scjscj and scj+1scj+1.}$

If you do not need to apply any moves, print a single integer $\mathrm{00 in\; the\; first\; line\; and\; either\; leave\; the\; second\; line\; empty\; or\; do\; not\; print\; it\; at\; all.}$

Examples

input

Copy

6
abcdef
abdfec

output

Copy

4
3 5 4 5 

input

Copy

4
abcd
accd

output

Copy

-1

Note

In the first example the string $\mathrm{ss changes\; as\; follows:\; "abcdef" \to \to "abdcef" \to \to "abdcfe" \to \to "abdfce" \to \to "abdfec".}$

In the second example there is no way to transform the string $\mathrm{ss into\; the\; string tt through\; any\; allowed\; moves.}$

$\mathrm{题意：只能交换s1的相邻元素，为最少需要次可以将s1换成s2}$

题解：暴力就行，如果不相等，从当前位置一直找，找到相等的元素然后一个个换过来

代码如下

#include <map>
#include <set>
#include <cmath>
#include <ctime>
#include <stack>
#include <queue>
#include <cstdio>
#include <cctype>
#include <bitset>
#include <string>
#include <vector>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <functional>
#define fuck(x) cout<<"["<<x<<"]";
#define FIN freopen("input.txt","r",stdin);
#define FOUT freopen("output.txt","w+",stdout);
//#pragma comment(linker, "/STACK:102400000,102400000")
using namespace std;
typedef long long LL;
typedef pair<int, int> PII;
const int maxn = 1e5+5;
int a[27];
int b[27];
int ans[ maxn];
int main(){

    int n;
    char str1[100];
    char str2[100];
    cin>>n>>str1>>str2;
    for(int i=0;i<n;i++){
        a[str1[i]-'a'+1]++;
        b[str2[i]-'a'+1]++;
    }
    int flag=1;
    int m=0;
    for(int i=1;i<=26;i++){
        if(a[i]!=b[i]){
            flag=0;
        }
    }
    if(flag==0){
        puts("-1");
    }else{
        for(int i=0;i<n;i++){
            if(str1[i]==str2[i]){
                continue;
            }else{
                for(int j=i; j<n; j++)
                    if(str1[j] == str2[i]){
                        for(int k=j-1; k>=i; k--){
                          ans[m++]=k+1;
                          swap(str1[k], str1[k+1]);
                      }
                      break;
                  }
              }
          }
          printf("%d
",m);
          for(int i=0;i<m;i++){
            printf("%d ",ans[i]);
        }
        puts("");
    }
    return 0;
}