Problem D

Intervals

You are given n closed, integer intervals [ai, bi] and n integers c1, ..., cn.

Problem

Write a program that:

Input

The first line of the input contains an integer n (1 ≤ n ≤ 50000) -- the number of intervals. The following n lines describe the intervals. The (i+1)-th line of the input contains three integers ai, bi and ci separated by single spaces and such that 0 ≤ ai ≤ bi ≤ 50000 and 1 ≤ ci ≤ bi - ai+1.

Output

The output contains exactly one integer equal to the minimal size of set Z sharing at least ci elements with interval [ai, bi], for each i=1,2,...,n.

Sample Input

5
3 7 3
8 10 3
6 8 1
1 3 1
10 11 1

Sample Output

6

ICPC/ACM Programming Contest - SWERC'2002 - University of Porto, Portugal