#include<stdio.h>
 #include<stdlib.h>
 #include<string.h>
 #include<ctype.h>
 #define max 1000005
  int prime ( int a, int b ){
 	
 	while ( a!= b ){
 		
 		if ( a > b ){

			a = a - b;
		}else{
			b = b - a;
		}
	}
	return a;
}
 int main(){
 
 	FILE *in, *out;
	char *number;
	int i, j, n, c = 0;
	number = ( char *) malloc(max * sizeof(char));
	in =  fopen("fractii.in","r");
	out = fopen("fractii.out","w");
	while ( fgets(number,max,in) != NULL ){
		
		c = 1;
		number =  strtok(number, "\n");
		sscanf(number,"%d",&n);
		for ( i = 1; i <= n; i++ ){
		
			for ( j = i+1; j <= n; j++ ){
			
				  if ( prime(i,j) == 1 ){
				  	printf("%d : (%d,%d)\n",n,i,j);
				  	c = c+2;
				  }
			}
		}
		fprintf(out, "%d\n",c);
	}
	fclose(in);
	fclose(out);
	return 0;
}