I have 2 spreadsheets. One has entries like: (Spreadsheet 2)

A B C D

5456 Mary 1 4
5456 Mary 2 3
2312 Mary 3 4
2145 Joe 2 2
2345 Joe 2 4
2345 Joe 3 4


The other one has entries like: (Spreadsheet 1)

A B

5456 Mary
2312 Mary
2145 Joe
2345 Joe

I want to put a formula in Spreadsheet 1 to count how many times the values
in Column A is in Spreadsheet 2.