Go: package main

import (
        "fmt"
        "math"
)

func main() {
        var v, t, h float64
        for {
                _, err := fmt.Scanf("%f", &v)
                if err != nil {
                        break
                }
                t = v / 9.8
                h = 4.9 * t * t
                n := math.Floor(h/5+1.0) + 1.0
                fmt.Printf("%d\n", int(n))
        }
}

C++: //何階から落とす？
#include<cstdio>
#include<cmath>

using namespace std;

int main(void){
	double in,y,h,t;
	int ans;

	while(scanf("%lf",&in)==1){
		t=in/9.8;
		y=4.9*(t*t);
		h=(y+5)/5;
		ans=ceil(h);
		printf("%d\n",ans);
	}

	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

int main(){
  double v;
  while (cin >> v) {
    double t = v / 9.8;
    double y = 4.9 * t * t;
    int kai = y / 5;
    if (kai % 5 == 0) {
      kai++;
    } else {
      kai += 2;
    }
    cout  << kai << endl;
  }
}

C++: #include<stdio.h>


int main(void){
	
	double v;
	
	while(scanf("%lf", &v) != EOF){
		double t = v/9.8;
		double y = 4.9*t*t;
		
		int n = y/5+2;
		if(y <= 9.8)n--;
		if((int)y == y)n--;
		
		printf("%d\n", n);
	}
	
	return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <cmath>
using namespace std;

int main(void) {
    double speed;
    while(cin >> speed) {
        double y = (speed / 2) * (speed / 9.8);
        int n = round((y + 5) / 5.0);
        cout << n << endl;
    }
    return(0);
}

C++: #include <iostream>
#include <cmath>
using namespace std;

int main(){
	cin.tie(0);
	ios::sync_with_stdio(false);

	double v;
	while(cin >> v){

		double t = v / 9.8;	// 2.59...
		double y = t * t * 4.9; // 

		/*// y = n * 5 - 5
		int n = 0;
		if(int(y + 5) % 5 == 0) n = (y + 5) / 5;
		else n = (y + 5) / 5 + 1;
		*/

		int n = 1;
		while(n * 5 - 5 < y){
			++n;
		}
		cout << n << endl;
	}

	return 0;
}

C++: #include<cstdio>
int main(){
  double v,t,y,i;
  while(scanf("%lf",&v)!=EOF){
    t = v/9.8;
    y = 4.9*t*t;
    for(i=0;i*5<y;i++);
    printf("%.0lf\n",i+1);
  }
  return(0);
}

C++: #include <iostream>
using namespace std;

int main() {

  double v;
  while(cin >> v) {
  double t = v/9.8;
  double y = 4.9*t*t;
  int ans = y/5+1+0.999999999;
  cout << ans  <<endl;
  }

  return 0;
}

C++: #include <iostream>
#include <cmath>
using namespace std;

int main(){
	double v, y;
	while(cin >> v){
		y = 4.9 * pow(v / 9.8, 2);
		int n = 0;
		for(n;;n++)if(y <= 5*n-5)break;
		cout << n << endl;
	}
	return 0; 
}

C++: #include <iostream>
using namespace std;

int main()
{
	double v;
	while(cin>>v){
		double t = v/9.8;
		double y = 4.9*t*t;
		int N;
		for(N=1;;N++){
			if(5*N-5>=y) break;
		}
		cout<<N<<endl;
	}
	return 0;
}

C++: #include <math.h>
#include <stdio.h>
#include <iostream>
using namespace std;

int main() {
	int n;
	long double v,y;
	while (cin >> v) {
		y = v * v / 9.8 / 2;
		n = y/5;
		if (n*5 < y)
			n++;
		cout << n + 1 << endl;
	}
	return 0;
}