#include <stdio.h>


// Define a structure to represent a point in 2D space

struct Point {

    int x;

    int y;

};


int main(void) {

    // Declare a structure variable and initialize its members

    struct Point p = {1, 2};


    // Print the values of the structure members

    printf("x = %d, y = %d\n", p.x, p.y);


    // Modify the structure members

    p.x = 3;

    p.y = 4;


    // Print the modified values of the structure members

    printf("x = %d, y = %d\n", p.x, p.y);


    return 0;

}

This program defines a structure called Point to represent a point in 2D space, with x and y members to represent the coordinates of the point. It declares a structure variable p of type struct Point and initializes its members. It then prints the values of the structure members and modifies them.

Here is an example of the output of this program:

x = 1, y = 2
x = 3, y = 4