Polycarpus likes studying at school a lot and he is always diligent about his homework. Polycarpus has never had any problems with natural sciences as his great-great-grandfather was the great physicist Seinstein. On the other hand though, Polycarpus has never had an easy time with history.

Everybody knows that the World history encompasses exactly $*n*$ events: the $*i*$-th event had continued from the year $*a*_{*i*}$ to the year $*b*_{*i*}$ inclusive ($*a*_{*i*} < *b*_{*i*}$). Polycarpus easily learned the dates when each of $*n*$ events started and ended (Polycarpus inherited excellent memory from his great-great-granddad). But the teacher gave him a more complicated task: Polycaprus should know when all events began and ended and he should also find out for each event whether it includes another event. Polycarpus' teacher thinks that an event $*j*$ includes an event $*i*$ if $*a*_{*j*} < *a*_{*i*}$ and $*b*_{*i*} < *b*_{*j*}$. Your task is simpler: find the number of events that are included in some other event.

Input

The first input line contains integer $*n*$ ($1 ≤ *n* ≤ 10^{5}$) which represents the number of events. Next $*n*$ lines contain descriptions of the historical events, one event per line. The $*i* + 1$ line contains two integers $*a*_{*i*}$ and $*b*_{*i*}$ ($1 ≤ *a*_{*i*} < *b*_{*i*} ≤ 10^{9}$) — the beginning and the end of the $*i*$-th event. No two events start or finish in the same year, that is, $*a*_{*i*} ≠ *a*_{*j*}, *a*_{*i*} ≠ *b*_{*j*}, *b*_{*i*} ≠ *a*_{*j*}, *b*_{*i*} ≠ *b*_{*j*}$ for all $*i*$, $*j*$ (where $*i* ≠ *j*$). Events are given in arbitrary order.

Output

Print the only integer — the answer to the problem.

Note

In the first example the fifth event is contained in the fourth. Similarly, the fourth event is contained in the third, the third — in the second and the second — in the first.

In the second example all events except the first one are contained in the first.

In the third example only one event, so the answer is 0.