csv 1.0.0-beta.5

extern crate csv;

use std::error::Error;
use std::io;
use std::process;

fn run() -> Result<u64, Box<Error>> {
    let mut rdr = csv::Reader::from_reader(io::stdin());
    let mut record = csv::ByteRecord::new();

    let mut count = 0;
    while rdr.read_byte_record(&mut record)? {
        if &record[0] == b"us" && &record[3] == b"MA" {
            count += 1;
        }
    }
    Ok(count)
}

fn main() {
match run() {
Ok(count) => {
println!("{}", count);
}
Err(err) => {
println!("{}", err);
process::exit(1);
}
}
}