#include<iostream>
#include<string>

using namespace std;

int main() {
	int flag=0;
	char a[10] = {}, b[10] = {};
	char c[10] = {};
	cin >> a >> b;

	for (int i = 0;i < 10;i++) {
	
		for (int j = 0;j < 10;j++) {
			if (a[i] == b[j]) {
				
				c[i] = b[j];
				b[j] = '^';
				break;
			}
		}
		
		for (int i=0;i<10;i++)
			if (a[i] == c[i]) { flag = 1; }
			else 
			{
				flag = 0;		
				break; 
			}
		}
	if (flag == 0) { cout << "NO"; }
	else { cout << "YES"; }

		cout << endl;
		
		return 0;
	}