#include <stdio.h>

int calcola( int a, int b )
{
	int c;
	c = a*b/2;
	return(c);
}

int main()
{
	int area;

	area = calcola( 10, 20 );
	printf( "Area:%d\n", area );

	area = calcola( 20, 30 );
	printf( "Area:%d\n", area );

	printf( "Area:%d\n", calcola( 5, 6 ) );
	return(1);
}