import java.util.ArrayList;
import java.util.Collections;
class Solution {
public long solution(long n) {
long answer = 0;
ArrayList<Long> nums = new ArrayList<>();
StringBuilder sb = new StringBuilder();
while(n!=0){
nums.add(n%10);
n/=10;
}
Collections.sort(nums);
Collections.reverse(nums);
for(long num: nums){
answer = answer*10 + num;
}
return answer;
}
}