num=int(input("Enter the number: "))
while(1):
    if(num%2!=0):
        print("\nPls enter an even number!")
        break
    else:
        def sum_even(n,x):
            sum=(x/2)*((n*2)+(x-1)*2)
            return sum
    a=int(input("\nEnter the number of integers to be taken: "))
    s=sum_even(num,a)
    print("\nThe sum is ",s)
         
   


    
        
        

    


        
    
        
    

    
    

