fn file_size(filename: String) throws -> i64 {
    mut result = 0
    mut file = File::open_for_reading(filename)
    mut buffer = [0u8; 1024] // Size of buffer is arbitrary
    while true {
        let read_bytes = file.read(buffer)
        if read_bytes == 0 {
            break
        }
        result += read_bytes as! i64
    }
    return result
}


fn main() {
    println("{}", file_size(filename: "input.txt"))
    println("{}", file_size(filename: "/input.txt"))
}