#include <stdio.h>
int main(void){

    char astr[11];
    char bstr[11];
    int a[10];
    int b[10];
    int i, j, w;
    for( i = 0; i < 10; i++ ){
        a[i] = 0;
        b[i] = 0;
    }

    scanf( "%s", astr );
    scanf( "%s", bstr );
    for( i = 0; i < 10; i++ ){
        if( astr[i] == '\0' ){
            break;
        }
        a[i] = ( int )astr[i];
        b[i] = ( int )bstr[i];
     }

	for( i = 0; i < 9; i++ ) {
		for ( j = i + 1; j < 10; j++ ){
			if (a[i] < a[j]) {
				w = a[i];
				a[i] = a[j];
				a[j] = w;
			}
			if (b[i] < b[j]) {
				w = b[i];
				b[i] = b[j];
				b[j] = w;
			}
		}
	}

	for( i = 0; i < 10; i++ ) {
	    if( a[i] != b[i] ){
	        printf( "NO\n" );
	        return( 0 );
	    }
	}
    printf( "YES\n" );
    return( 0 );
}