public class Solution {
public int solve(String a) {
HashMap<Character, Integer> hm = new HashMap<>();
for(int i=0; i<a.length(); i++) {
Character c=a.charAt(i);
if(hm.containsKey(c))
hm.put(c, hm.get(c)+1);
else
hm.put(c, 1);
}
int flag=0;
for(Map.Entry<Character, Integer> m : hm.entrySet())
if((m.getValue()&1)==1) flag++;
return flag<2?1:0;
}
}