Point on the plane (square)

Description

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Given a square and several points, find the number of points in the square (including points on the sides of the square). Here the four sides of the square are parallel to the (x) and (y) coordinate axes.

Format

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Input

The four integers (x), (y), (l), and (n) in the first line are the (X) and (Y) coordinates of the lower left corner of the square, side length and the number of points ((-10000≤x,y≤10000),(l≤10000),(n≤10000));
The next (n) lines have two numbers (x_i) and (y_i), which represent the coordinates of each point, (-10000≤x_i, y_i≤10000).

Output

An integer representing the number of points contained in the square.

Sample

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Input

0 0 5 5
1 2
3 4
6 7
5 3
2 8

Output

3

Sample Code

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#include <cstdio>
inline bool btw(int a, int b, int c){
	return a>=b && a<=c;
}
int main(){
    freopen("square.in", "r", stdin);
    freopen("square.out", "w", stdout);
    int x, y, l, n;
    scanf("%d %d %d %d", &x, &y, &l, &n);
    int ans=0;
    while (n--){
		int u, v;
		scanf("%d %d", &u, &v);
		ans+= (btw(u, x, x+l) && btw(v, y, y+l));
	}
	printf("%d
", ans);
    return 0;
}