既然TLE，那就不用循环了呗！

LONG LONG法（100分）

#include <iostream>
using namespace std;

int main() {
    long long x, y;
    cin >> x >> y;
    
    auto compute = [x, y](long long k) {
        return (y / k) - ((x - 1) / k);
    };
    
    long long count_7 = compute(7);
    
    long long count_14 = compute(14);
    long long count_21 = compute(21);
    long long count_35 = compute(35);
    
    long long count_42 = compute(42);
    long long count_70 = compute(70);
    long long count_105 = compute(105);
    long long count_210 = compute(210);
    
    long long sum_single = count_14 + count_21 + count_35;
    long long sum_double = count_42 + count_70 + count_105;
    long long sum_triple = count_210;
    
    long long exclude = sum_single - sum_double + sum_triple;
    long long result = count_7 - exclude;
    
    cout << result;
    
    return 0;
}