#!/bin/bash

grid=()
risks_grid=()
i_max=0
j_max=0
while read line; do
  j_max=${#line}
  for ((j=0; j<j_max;j++)); do
    grid+=( ${line:$j:1} )
    risks_grid+=( -1 )
  done
  i_max=$((i_max+1))
done
risks_grid[0]=0

detected_paths=1
while [ $detected_paths -eq 1 ]; do
  detected_paths=0
  for ((i=0; i<i_max; i++)); do
    for ((j=0; j<j_max; j++)); do
      lowest_risk=$((9*i_max*j_max))
      if [ $j -gt 0 ] && [ ${risks_grid[$((i*j_max+j-1))]} -lt $lowest_risk ] \
              && [ ${risks_grid[$((i*j_max+j-1))]} -ge 0 ]; then
        lowest_risk=${risks_grid[$((i*j_max+j-1))]}
      fi
      if [ $j -lt $((j_max-1)) ] && [ ${risks_grid[$((i*j_max+j+1))]} -lt $lowest_risk ] \
              && [ ${risks_grid[$((i*j_max+j+1))]} -ge 0 ]; then
        lowest_risk=${risks_grid[$((i*j_max+j+1))]}
      fi
      if [ $i -gt 0 ] && [ ${risks_grid[$(((i-1)*j_max+j))]} -lt $lowest_risk ] \
              && [ ${risks_grid[$(((i-1)*j_max+j))]} -ge 0 ]; then
        lowest_risk=${risks_grid[$(((i-1)*j_max+j))]}
      fi
      if [ $i -lt $((i_max-1)) ] && [ ${risks_grid[$(((i+1)*j_max+j))]} -lt $lowest_risk ] \
              && [ ${risks_grid[$(((i+1)*j_max+j))]} -ge 0 ]; then
        lowest_risk=${risks_grid[$(((i+1)*j_max+j))]}
      fi
      if [ ${risks_grid[$((i*j_max+j))]} -lt 0 ] \
	      || [ ${risks_grid[$((i*j_max+j))]} -gt $((grid[i*j_max+j]+lowest_risk)) ]; then
        risks_grid[$((i*j_max+j))]=$((grid[i*j_max+j]+lowest_risk))
	detected_paths=1
      fi
    done
  done
done

echo ${risks_grid[$((i_max*j_max-1))]}