#include <cstdio>

int cmmdc(int a, int b)
{
    if(!b) return a;
    return(cmmdc(b, a % b));
}

int main(void)
{
    freopen("fractii.in", "r", stdin);
    freopen("fractii.out", "w", stdout);
    int nV, nC;
    scanf("%d", &nV);
    nC = 2 * nV - 1;
    for(int i(2); i <= nV / 2 + 1; i++)
        for(int j(i + 1); j <= nV; j++)
            if(cmmdc(i, j) == 1) nC +=2;
    printf("%d", nC);
    return 0;
}