#!/usr/bin/env tclsh8.6

set row 0
while {[gets stdin line] >= 0} {
  set col 0
  foreach c [split $line {}] {
    set grid($row,$col) $c
    incr col
  }
  incr row
}

# set steps 100
# if {[llength $argv]} {set steps [lindex $argv 0]}

proc energize {r c} {
  global grid row col
  if {$r < 0 || $c < 0} return
  if {$r >= $row || $c >= $col} return

  incr grid($r,$c)
  if {$grid($r,$c) == 10} {
    foreach dr {-1 0 1} {
      foreach dc {-1 0 1} {
        if {$dr == 0 && $dc == 0} continue
        energize [expr {$r + $dr}] [expr {$c + $dc}]
      }
    }
  }
}

set step 0
while 1 {
  incr step
  set flash 0
  for {set r 0} {$r < $row} {incr r} {
    for {set c 0} {$c < $col} {incr c} {
      energize $r $c
    }
  }
  for {set r 0} {$r < $row} {incr r} {
    for {set c 0} {$c < $col} {incr c} {
      if {$grid($r,$c) > 9} {
        set grid($r,$c) 0
	incr flash
      }
    }
  }
  if {$flash == $row * $col} {puts $step; break}
}