题解

#include <bits/stdc++.h>
using namespace std;
int a[1000010];
int ans;
int main() {
int n, b;
cin >> n >> b;
a[1] = 1;
for (int i = 2; i <= n; i++) {
if (!a[i]) {
for (int j = i; j <= n; j += i)
a[j] = i;
}
}
for (int i = 1; i <= n; i++) {
if (a[i] <= b)
ans++;
}
cout << ans;
return 0;
}