#!/usr/bin/env python3

from sys import stdin, stdout, argv
from time import time

detailed = '-d' in argv
start = time()
last = start
for line in stdin:
    now = time()
    duration = now - start
    diff = now - last
    last = now
    if detailed:
        stdout.write(f"{duration:0.6f} [{diff:0.6f}] {line}")
    else:
        stdout.write(f"{duration:0.6f} {line}")