#!/usr/bin/env tclsh

set y 0
while {[gets stdin line] >= 0} {
  if {$line eq {}} continue
  set x 0
  foreach c [split $line {}] {
    set grid($x,$y) $c
    incr x
  }
  set width $x
  incr y
}
set height $y

set x 0
set y 1
set trees 0
while {$y < $height} {
  set x [expr {($x+3) % $width}]
  if {$grid($x,$y) eq "#"} {incr trees}
  incr y
}
puts $trees