We need a three-stage time-space-time switch with n=100. we use 10 tsis at the first and third stages and 4 crossbars at the middle stage. calculate the total number of crosspoints.

do not use any of these common illegal characters/symbols:

# pound

% percent

& ampersand

{ left curly bracket

} right curly bracket

\ back slash

< left angle bracket

> right angle bracket

* asterisk

? question mark

/ forward slash

  blank spaces

$ dollar sign

! exclamation point

' single quotes

" double quotes

: colon

@ at sign