CodeForces 372 A Counting Kangaroos is Fun

A. Counting Kangaroos is Fun

time limit per test

1 second

memory limit per test

256 megabytes

input

standard input

output

standard output

There are n kangaroos with pockets. Each kangaroo has a size (integer number). A kangaroo can go into another kangaroo's pocket if and only if the size of kangaroo who hold the kangaroo is at least twice as large as the size of kangaroo who is held.

Each kangaroo can hold at most one kangaroo, and the kangaroo who is held by another kangaroo cannot hold any kangaroos.

The kangaroo who is held by another kangaroo cannot be visible from outside. Please, find a plan of holding kangaroos with the minimal number of kangaroos who is visible.

Input

The first line contains a single integer — n (1 ≤ n ≤ 5·105). Each of the next n lines contains an integer si — the size of the i-th kangaroo(1 ≤ si ≤ 105).

Output

Output a single integer — the optimal number of visible kangaroos.

Examples

input

825769842

output

5

input

891626583

output

5

二分做不动了……直接暴力了这题。

因为最多的情况就是前面的和后面的一对一组成一组，所以滚的时候直接从中间开始滚。

#include<stdio.h>#include<string.h>#include<math.h>#include<algorithm>using namespace std;int n;int a[511111];int main(){int i,j;while(~scanf("%d",&n)){memset(a,0,sizeof(a));for(i=0;i<n;i++)scanf("%d",&a[i]);sort(a,a+n);int ans=0;i=n-1;for(j=n/2-1;j>=0;j--){if(a[i]>=2*a[j]){ans++;i--;}}printf("%d\n",n-ans);}return 0;}