double readDouble(){
	char c=getchar();
	while ((c>'9' || c<'0') && c!='.')c=getchar();
	double r=0.0;
	if (c!='.'){
		r=(double)(c-'0');
		while (c=getchar(),'0'<=c && c<='9')
			r=10.0*r+(double)(c-'0');
	}
	if (c=='.'){
		double t=0.1;
		while (c=getchar(),'0'<=c && c<='9')
			r=r+t*(c-'0'),t=t*0.1;
	}
	return r;
}