package main

import (
	"bufio"
	"log"
	"os"
)

// readlines reads lines from stdin.
// it returns them as an array of strings
func readlines() []string {
	lines := []string{}

	scanner := bufio.NewScanner(os.Stdin)
	for scanner.Scan() {
		lines = append(lines, scanner.Text())
	}

	if err := scanner.Err(); err != nil {
		log.Fatal(err)
	}

	return lines
}

// buildGraph parses lines into costs for graph
func buildGraph(lines []string) [][]int {
	graph := make([][]int, len(lines))

	for i, line := range lines {
		graph[i] = make([]int, len(line))
		for j, r := range line {
			graph[i][j] = int(r - '0')
		}
	}

	return graph
}