// a = 97, z = 122

#include <stdio.h>

#include <string.h>

int main(void)
{

    int numberOfCaseT;
    char firstChar[100][100], secChar[100][100];
    int engBasicFirst[26], engBasicSec[26];
    int firstLen[100], secLen[100];


    scanf("%d",&numberOfCaseT);
    int i;
    for(i=0;i<numberOfCaseT;i++){
        scanf("%s %s", &firstChar[i], &secChar[i]);
    }

    for(i=0; i<numberOfCaseT;i++){

        int j, k = 0;

    firstLen[i] = strlen(firstChar[i]);
    secLen[i] = strlen(secChar[i]);
        if(strcmp(firstChar[i], secChar[i])==0){
        printf("No.\n");
        }
    else if(firstLen[i]!=secLen[i]){
        printf("No.\n");
    }else{
        for(j=0;j<firstLen[i];j++){
            engBasicFirst[firstChar[i][j]-97]++;
            engBasicSec[secChar[i][j]-97]++;
        }
        k =0;
        while(k<27){
            if(engBasicFirst[k]!=engBasicSec[k]){
                printf("No.\n");
                break;
            }
            k++;
        }if(k==27){
            printf("Yes\n");
        }

    }

    }

    return 0;

}