Excel: How do I take the first character of 3 different cells and last 4 numbers of 1 cell and combine them?

if a1 is bob, b1 is james, c1 is ricky, and d1 is a ssn#(123-45-6789), how do i combine the first character开发者_StackOverflowsos a1, b1, and c1 and the last four of the ssn so that it says bjr6789?

=LEFT(A1,1)&LEFT(B1,1)&LEFT(C1,1)&RIGHT(D1,4)

Edit: Changed to use row1.