#include <stdio.h>
#include <stdlib.h>
int main(){
	freopen("fractii.in", "r", stdin);
    freopen("fractii.out", "w", stdout);

	int n, i, j, size = 1, k,ok = 1;
	float *cresc, *v;
	scanf("%d",&n);
	v =(float *) malloc(n * sizeof(float *));
	
	cresc = (float *) malloc(n*n*sizeof(float*));
	cresc[0] = 1;

	for(i = 0; i < n; i++)
		v[i] = i + 1;

	for(i = 0; i < n; i++){
		for(j = i+1; j < n; j++){
			ok = 1;
			for( k = 1; k < size; k++){
				if( cresc[k] == v[i]/v[j]){
					ok = 0;
				}
			}
			if( ok == 1){
				size++;
				cresc[size] = v[i]/v[j];
			}
		}
	}

	printf("%d",(size-1)*2 +1);
		
}