Overlaying Raw Points on a Box Plot

Ironbark Manufacturing found supervisors trusting box summaries drawn from four parts, so every box now has the individual measurements scattered over it as dots, nudged sideways so overlapping ones stay visible. The caption states how many dots there are, because a box drawn over five parts and one drawn over five hundred look identical otherwise.

Task: Print how many measurements will be drawn as dots.

Input

The first line holds one integer n, the number of measurements. Each of the next n lines holds a machine name and one measurement, separated by a single space. Machine names contain no spaces.

Output

One line holding a single whole number: how many measurements there are in total, across every machine. Every measurement gets its own dot, including repeats of the same value.

Example:

Input:
3
A 10
B 20
A 30

Output:
3