#!/bin/bash
mapfile -t depth
nd=${#depth[@]}
prev=$(( depth[0] + depth[1] + depth[2] ))
n=0

for ((i=0; i <= nd-3; i++)); do
  sum=$(( depth[i] + depth[i+1] + depth[i+2] ))
  ((sum > prev)) && ((n++))
  prev=$sum
done

echo "$n"