#include<stdio.h>

void fractii_ireductibile(int n)
{
    FILE *fout;
    fout=fopen("fractii.out","w");

    int p,q,i,j,c=0;
    for(i=1;i<=n;i++)
        for(j=1;j<=n;j++)
            if(i!=1 && j!=1 && (i%j==0 || j%i==0) || (i%2==0 && j%2==0))
                continue;
            else
            {
                printf("%d/%d ",i,j);
                c++;
            }
    fprintf(fout,"%d",c);
}

int main()
{
    FILE *fin;
    fin=fopen("fractii.in","r");

    int n;
    fscanf(fin,"%d",&n);
    fractii_ireductibile(n);
    return 0;
}