1018-打电话

代码纯属原创，如有雷同，纯属巧合！

#include <stdio.h>
int main(void)
{
	double x;
	int time;
	scanf("%lf",&x);
	if(x<=0.5)
		time=3;
	else
		time=3+(x-0.4)*10/2;
	printf("%d",time);
	return 0;
}