#!/usr/bin/env awk

BEGIN {
  safe = 0
}
{
  if ($2 > $1) {
    order = 0
  } else {
    order = 1
  }
  for (i = 1; i < NF; i++) {
    j = i + 1
    if ( $i < $j && order == 1 ) {
      next
    } else if ( $i > $j && order == 0) {
      next
    }
    if ( $i < $j ) {
      diff = $j - $i
    } else { 
      diff = $i - $j
    }
    if (diff > 3 || diff < 1) {
      next
    }
  }
  safe += 1
}
END {
  print safe
}