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 Rust (1.15.1) (judge verdict: Wrong Answer)

fn input() -> String{
    let mut buf = String::new();
    std::io::stdin().read_line(&mut buf).expect("Error");
    buf[0..buf.len() - 2].to_string()
}
fn main(){
    let s = &input();
    let v = ["SUN", "MON", "TUE", "WED", "THU", "FRI", "SAT"];
    let mut i :usize = 7;
    for _w in &v{
        if s != _w{
            i -= 1;
        }else{
            println!("{}", i);
            break;
        }
    }
    
}