codeforces559B

Equivalent Strings

Today on a lecture about strings Gerald learned a new definition of string equivalency. Two strings a and b of equal length are called equivalent in one of the two cases:

They are equal.
If we split string a into two halves of the same size a₁ and a₂, and string binto two halves of the same size b₁ and b₂, then one of the following is correct:
1. a₁ is equivalent to b₁, and a₂ is equivalent to b₂
2. a₁ is equivalent to b₂, and a₂ is equivalent to b₁

As a home task, the teacher gave two strings to his students and asked to determine if they are equivalent.

Gerald has already completed this home task. Now it's your turn!

Input

The first two lines of the input contain two strings given by the teacher. Each of them has the length from 1 to 200 000 and consists of lowercase English letters. The strings have the same length.

Output

Print "YES" (without the quotes), if these two strings are equivalent, and "NO" (without the quotes) otherwise.

Examples

Input

aaba
abaa

Output

YES

Input

aabb
abab

Output

NO

Note

In the first sample you should split the first string into strings "aa" and "ba", the second one — into strings "ab" and "aa". "aa" is equivalent to "aa"; "ab" is equivalent to "ba" as "ab" = "a" + "b", "ba" = "b" + "a".

In the second sample the first string can be splitted into strings "aa" and "bb", that are equivalent only to themselves. That's why string "aabb" is equivalent only to itself and to string "bbaa".

sol：显然是分治，Hash判断字符串是否相等

不知道为什么一直TLE，至今仍然死在第91个点，弃疗了。

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
inline ll read()
{
    ll s=0;
    bool f=0;
    char ch=' ';
    while(!isdigit(ch))
    {
        f|=(ch=='-'); ch=getchar();
    }
    while(isdigit(ch))
    {
        s=(s<<3)+(s<<1)+(ch^48); ch=getchar();
    }
    return (f)?(-s):(s);
}
#define R(x) x=read()
inline void write(ll x)
{
    if(x<0)
    {
        putchar('-'); x=-x;
    }
    if(x<10)
    {
        putchar(x+'0');    return;
    }
    write(x/10);
    putchar((x%10)+'0');
    return;
}
#define W(x) write(x),putchar(' ')
#define Wl(x) write(x),putchar('
')
const int N=2000005;
const ll Power=97,Mod=19260817;
int n;
char S[2][N];
ll Hash[2][N],Base[N];
inline ll Calc(int l,int r,int o)
{
    return (Hash[o][r]-Hash[o][l-1]+Mod)%Mod*Base[n-r]%Mod;
}
inline bool Equal(int l1,int r1,int l2,int r2)
{
    if(Calc(l1,r1,0)==Calc(l2,r2,1)) return 1;
    if((r1-l1+1)&1) return 0;
    if(Equal(l1,(l1+r1)>>1,l2,(l2+r2)>>1)&&Equal(((l1+r1)>>1)+1,r1,((l2+r2)>>1)+1,r2)) return 1;
    if(Equal(l1,(l1+r1)>>1,((l2+r2)>>1)+1,r2)&&Equal(((l1+r1)>>1)+1,r1,l2,(l2+r2)>>1)) return 1;
    return 0;
}
int main()
{
    freopen("data.in","r",stdin);
    int i,j;
    scanf("%s%s",S[0]+1,S[1]+1);
    n=strlen(S[0]+1);
    Base[0]=1;
    for(i=0;i<2;i++)
    {
        Hash[i][0]=0;
        for(j=1;j<=n;j++)
        {
            Base[j]=1ll*Base[j-1]*Power%Mod;
            Hash[i][j]=1ll*(Hash[i][j-1]+S[i][j]*Base[j]%Mod)%Mod;
        }
    }
    if(Equal(1,n,1,n)) puts("YES");
    else puts("NO");
    return 0;
}
/*
Input
aaba
abaa
Output
YES

Input
aabb
abab
Output
NO

Input
a
a
Output
YES
*/

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