Function to find greatest number that us
int findGreatest ( int arr [ ] , int n ) { int result = -1 ; for ( int i = 0 ; i < n ; i ++ ) for ( int j = 0 ; j < n - 1 ; j ++ ) for ( int k = j + 1 ; k < n ; k ++ ) if ( arr [ j ] * arr [ k ] == arr [ i ] ) result = max ( result , arr [ i ] ) ; return result ; }