#include <stdio.h>
#define for_i(i, range, inner)                                                 \
    {                                                                          \
        int i;                                                                 \
        for (i = 0; i < range; i++)                                            \
            inner;                                                             \
    }
#define for_wrapper(a, b, c, d)                                                \
    {                                                                          \
        a;                                                                     \
        for (; b; c)                                                           \
            d;                                                                 \
    }

int main() {
    int n, a[1000] = {0};
    int sum = 0;
    scanf("%d", &n);
    for_wrapper(int i = 1, i <= n, i++, {
        for_wrapper(int j = i - 1, j < n, j += i, {
            a[j] = !a[j];
        });
    });
    for_i(i, n, sum += a[i]);
    printf("%d", sum);
    return 0;
}