#include <stdio.h>

int main(void) {
	//LIFO-stack structure for local variables
	//initialization of variables is ignored
	//push
	int a1, a2, a3, a4, a5;
	{
		//push
		int b1, b2, b3, b4;
		{
			//push
			int c1, c2, c3;
			//computation, temporaries stored(pushed) in da stack then pop'd out
			int a=(a1+a2)+a3+(b1+c1);
		}	//pop
	}//pop
	return 0;
}//pop (not )