#include <time.h>
int RandInit() { time_t t; time( &t ); srand( t ); return ( (int) t ); }
int Rand( int N ) { return (int)( (double) rand() / ( (double) RAND_MAX + 1 ) * N ); }
RandInit();
cx1 = Rand( 41 ) - 20; cy1 = Rand( 41 ) - 20;