#include <cstdio>
#include <vector>
#include <cmath>

int main(void)
{
    freopen("fractii.in", "r", stdin);
    freopen("fractii.out", "w", stdout);
    int nV = 0, nS = 0, nC = 0;
    scanf("%d", &nV);
    std::vector<int> myV;
    bool *myB = new bool[nV + 1];
    for(int i = 0; i <= nV; i++)
    	myB[i] = true;
    for(int i(2); i <= sqrt(nV); i++)
        if(myB[i])
            for(int j(i * i); j <= nV; j += i)
                myB[j] = false;
    for(int i(2); i <= nV; i++)
        if(myB[i])
        {
            nS++;
            myV.push_back(i);
        }
    delete[] myB;
    int *nArr = new int[nV + 1];
    for(int i(2); i <= nV; i++)
    {
    	int j = 0;
    	while(i % myV[j] != 0)
    		j++;
    	nArr[i] = myV[j];
    }
    nC = (nV - 1) * 2 + 1;
	for(int i(2); i <= nV; i++)
    	for(int j(i + 1); j <= nV; j++)
    		if(i % nArr[j] != 0 && j % nArr[i] != 0) nC += 2;
    printf("%d ", nC);
    return 0;
}