Write a function with the header

 int postalCode(const char code[ ] )

that receives the address of a null-terminated string (code[ ]) and returns 1 if the code is a valid Canadian postal code and 0 otherwise.  A Canadian postal code consists of exactly 6 characters: the first, third and fifth are alphabetic, while the second, fourth and sixth are numeric.  Your function does not change the contents of code[ ]. 

The following calls

 printf("%d\n", postalCode("M6P2T4"));
 printf("%d\n", postalCode("M6P.T4"));
 printf("%d\n", postalCode("M6P 2T4"));

display respectively:

 1
 0
 0

That is, the first code is valid, the second code is invalid because the fourth character is not numeric, and the third code is invalid because of the string contains 7 characters.