Problems

# Film Festival

# Film Festival

The festival of French cinema, which will be held over one day, will demonstrate **n** films, for each of them we know the start time and and duration time of the show. Viewing takes place in a theater having sufficient number of halls for demonstrations, the transition between the halls takes less than a minute, that is, as soon as next minute after the previous session, you can catch the other. What is the largest number of films can be watched completely?

#### Input

First line contains the number of films **n** (**1** ≤ **n** ≤ **100**). Next **n** lines contains the beginning and the length of the **i**-th (**1** ≤ **i** ≤ **n**) film - two integers in format **h** hours **m** minutes (**0** ≤ **h** ≤ **23**, **0** ≤ **m** ≤ **59**).

#### Output

Print the maximum number of visited sessions.

Input example #1

3 10 10 1 20 11 15 1 30 11 40 2 0

Output example #1

2