class Solution {
public int solution(int left, int right) {
int answer = 0;
for(int i = left; i <= right; i++){
int num = i;
int count = 0;
for(int j = 1; j <= num; j++){
if(num % j == 0){
count++;
}
}
if(count % 2 == 0){
answer += i;
}else{
answer -= i;
}
}
return answer;
}
}