#include<bits/stdc++.h>

using namespace std;
int sum = 0;
int sushu(int n) {
	sum = 0;
	for (int i = 1; i <= n; i++) {
		if (n % i == 0) {
			continue;
		} else {
			sum++;
		}
	}
	return sum;
}

int main() {
	int a, b, sum1 = 0;
	cin >> a >> b;
	for (int i = a; i < (b - a) + 1; i++) {
		sum1 += sushu(i);
	}
	cout << sum1;
	return 0;
}

这题判断素数的函数有了，计数器也有了，唯独第一个事例不对