Problem:
Score : 100 points

Problem Statement

Given is a string S representing the day of the week today.

S is SUN, MON, TUE, WED, THU, FRI, or SAT, for Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, and Saturday, respectively.

After how many days is the next Sunday (tomorrow or later)?

Constraints

S is SUN, MON, TUE, WED, THU, FRI, or SAT.

Input

Input is given from Standard Input in the following format:

S

Output

Print the number of days before the next Sunday.

Sample Input 1

SAT

Sample Output 1

1

It is Saturday today, and tomorrow will be Sunday.

Sample Input 2

SUN

Sample Output 2

7

It is Sunday today, and seven days later, it will be Sunday again.

Solution in Go (1.6) (judge verdict: Accepted)

package main

import (
  "io"
  "bufio"
  "strings"
  "fmt"
  "os"
)
 
func nextDate(date string) (d int) {
  switch date {
    case "SUN":
      d = 7
    case "MON":
      d = 6
    case "TUE":
      d = 5
    case "WED":
      d = 4
    case "THU":
      d = 3
    case "FRI":
      d = 2
    case "SAT":
      d = 1
    default:
      d = 0
  }
  return
}
 
func main() {
  buf := bufio.NewReaderSize(os.Stdin, 1024)
  date := readLine(buf)
  fmt.Fprintf(os.Stdout, "%v\n", nextDate(date))
}
 
func readLine(reader *bufio.Reader) string {
  str, _, err := reader.ReadLine()
  if err == io.EOF {
    return ""
  }
  return strings.TrimRight(string(str), "\r\n")
}
 
func checkErr(err error) {
  panic(err)
}