AIZU 0024 Physical Experiments

Description

Ignoring the air resistance, velocity of a freely falling object v after t seconds and its drop y in t seconds are represented by the following formulas:

A person is trying to drop down a glass ball and check whether it will crack. Your task is to write a program to help this experiment.

You are given the minimum velocity to crack the ball. Your program should print the lowest possible floor of a building to crack the ball. The height of the N floor of the building is given by 5 × N - 5.

Input

The input consists of multiple datasets. Each dataset, a line, consists of the minimum velocity to crack the ball. The input ends with EOF.

Output

For each dataset, print the lowest possible floor where the ball cracks.

Sample Input

25.4
25.4

Output for the Sample Input

8
8

此題用來簽到真是極好的，題目很水，直接上代碼了

#include <iostream> 
#include <cmath> 
using namespace std; 
int main() 
{
       double y,t,mv; 
       while(cin>>mv)
      { 
              t=mv/9.8; y=t*t*4.9; double n=(y+5)/5;        
              cout<<ceil(n)<<endl; 
      } 
      return 0; 
     }