Function to count pairs whose sum of GCD and LCM is equal to N
int countPair ( int N ) { int count = 0 ; for ( int i = 1 ; i <= N ; i ++ ) { for ( int j = 1 ; j <= N ; j ++ ) { if ( __gcd ( i , j ) + lcm ( i , j ) == N ) { count ++ ; } } } return count ; }