output should be :

comparing %hash1 with  %hash 2 : found 1 match which is D
comparing %hash1 with  %hash 3 : found 1 match which is D

comparing %hash2 with  %hash 3 : found 1 match which is D and J 


my %hash1 = (
    A => 1,
    B => 2,
    C => 3,
    D => 4,
);

my %hash2 = (
    D=>1
    E =>2,
    F => 3,
    G => 4,
    H => 5,
     I => 6,
	 J=>7
);

my %hash3 = (
    J=>1
    K =>2,
    L => 3,
    M => 4,
    N => 5,
    O => 6,
    P=>7
     Q =>8,
     R =>9,
     S =>10,
   T => 11,
    U =>12,
    D=>13,
);