/*
2011 01 07 ??

????????????????????????????????????????
????
???????????????????????????
????
???????????????????YES? 
????NO???YES?NO???????

?? 1000012760
*/


int main(){
	char a[100], b[100];
	int la= 0, lb= 0, same= 1, i= 0, j= 0, aused[100]= {0}, bused[100]= {0};

	cin>>a>>b;

	la= strlen(a);
	lb= strlen(b);

	if(la!= lb)
		cout<<"NO"<<endl;
	else{
		for(i= 0; i< la; i++){
			for(j= 0; j< lb; j++){
				if(a[i]== b[j] && bused[j]== 0){
					bused[j]= 1;
					aused[i]= 1;
					break;
				}
			}
			if(aused[i]== 0){
				cout<<"NO"<<endl;
				return 0;
			}
		}
		for(i= 0; i< lb; i++){
			if(bused[i]== 0){
				cout<<"NO"<<endl;
				return 0;
			}
		}
		cout<<"YES"<<endl;
	}
	return 0;
}