Problem:
Set Difference

Find the difference of two sets $A = \{a_0, a_1, ..., a_{n-1}\}$ and $B = \{b_0, b_1, ..., b_{m-1}\}$, $A - B$.

Input

The input is given in the following format.

$n$
$a_0 \; a_1 \; ... \; a_{n-1}$
$m$
$b_0 \; b_1 \; ... \; b_{m-1}$

Elements in $A$ and $B$ are given in ascending order. There are no duplicate elements in each set.

Output

Print elements in the difference in ascending order. Print an element in a line.

Constraints

$1 \leq n, m \leq 200,000$

$0 \leq a_0 < a_1 < ... < a_{n-1} \leq 10^9$

$0 \leq b_0 < b_1 < ... < b_{m-1} \leq 10^9$

Sample Input 1

5
1 2 3 5 8
2
2 5

Sample Output 1

1
3
8

Solution in C (judge verdict: Accepted)

#include <stdio.h>

int a[200010],b[200010];
int main(){
	int n,m;
	scanf("%d",&n);
	for(int i=0;i<n;i++)scanf("%d",a+i);
	scanf("%d",&m);
	for(int i=0;i<m;i++)scanf("%d",b+i);
	a[n]=b[m]=2e9;
	for(int i=0,j=0;i<n;){
		if(a[i]<b[j])printf("%d\n",a[i++]);
		else if(a[i]>b[j])j++;
		else i++,j++;
	}
}