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