Go: package main

import (
	"bufio"
	"os"
	"strconv"
	"fmt"
)

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	for scanner.Scan() {
		a, _ := strconv.ParseFloat(scanner.Text(), 64)
			t := a/9.8
			x := t*t*4.9
			fmt.Printf("%d\n", int(x))
	}
}

C++:  
 #include<iostream>
 #include<stdio.h>
 #include<string>
 #include<math.h>
 #include<iomanip>
 #include<algorithm>
 #include<string.h>
 #include<cctype>
 #include<map>
 #include<set>
 #include<vector>
 #include<sstream>
 #include<stack>
 
 using namespace std;
 
 double abs(double x)
 {
   if(x<0) return -x;
   else return x;       
 }
  
 int main()
 {
   double v;
   while(cin>>v)
   {
     double t=v/9.8;
     double h=4.9*t*t;
     int N=(int)((h+5)/5)+1;
     cout<<N<<endl;
   }
   //while(1);      
   return 0;    
 }

C++: #include<iostream>
#include<cmath>

using namespace std;
/*
	v = 9.8t
	y = 4.8t^2
	割れる速度になるtを求め、その時間でどのくらいの距離になるか計算する。
*/
int main() {
	double v;

	while (cin >> v) {
		double t = v / 9.8;
		double y = 4.8 * t * t;

		int N = static_cast<int>(ceil(y / 5) + 1);

		cout << N << endl;
	}
}

C++: #include <cstdio>
#include <cstdlib>
#include <iostream>
#include <string>
#include <cmath>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>

using namespace std;

int main(){
    double in,ans;
    
    while(scanf("%lf",&in)!=EOF){
        ans=in*in/98+1;
        printf("%.0lf\n",ans);
    }
    
    return 0;
}

C++: 
#include <iostream>
#include <string>
#include <stack>
#include <math.h>
#include <algorithm>
#include <cstdlib>
#include <ctime>
#include <vector>

using namespace std;





int main()
{
	double v;
	double h;
	int n = 1;
	while (cin >> v) {
		h = 4.9*(v / 9.8)*(v / 9.8);
		while (h > 5 * (n - 1)) {
			n++;
		}
		cout << n << endl;
	}


	return 0;
}

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

int main() {

  double d;
  while(cin>>d) {
    double t = d/9.8;
    double h = 4.9*t*t;

    for(int i=1; ;i++) {
      if(5*i-5>h) {
        cout<<i<<endl;
        break;
      }
    }
  }
}

C++: #include<iostream>
using namespace std;
int main()
{
long double v,n;
int N;
while(cin>>v)
{
n=(4.9*((v/9.8)*(v/9.8)))/5+1;
N=n*10000;	
if(N%10000==0)
{
	cout<<N/10000<<endl;
}
else if(N%10000!=0)
{
	cout<<N/10000+1<<endl;
}
}
return 0;
}

C++: 

#include<cstdio>
#include<iostream>
#include<math.h>
using namespace std;

int main(){

    double v,s,floorH;
    int i;
    while(cin>>v){
        s=(v/9.8)*(v/2);
        for(i=1;i;i++){
            floorH=5*i-5;
            if(floorH>=s){
                cout<<i<<endl;
                break;
            }
        }
    }

return 0;
}

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

int main(){
  double v, h;
  int f;

  while(cin>>v){
    h=v*v/19.6;
    f=(int)h/5+2;
    printf("%d\n", f);
  }

  return 0;
}

C++: 
#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <cmath>
#include <utility>

#define ll (long lon
#define REP(i,n) for(int i = 0;i<(int)n;i++)
#define FOR(i,a,b) for(int i = (a);i < (b);i++)
#define RFOR(i,a,b) for(int i = (a);i>(b);i--)

using namespace std;

int main (void){
    
    double min_v;
    while(cin >> min_v)
    {
        int i = 1;
        double h = (min_v / 9.8)*(min_v/9.8)*4.9;
        while((5*i-5)<= h)
            i++;
        cout << i << endl;
    }
    
    return 0;
}

C++: #include <iostream>
#include <cmath>

using namespace std;

int main()
{
  double speed, v, t;
  int height;
  int N;

  while (cin >> speed) {
    N = 1;
    while (1) {
      height = 5 * N - 5;
      t = sqrt(height / 4.9);

      v = 9.8 * t;
      if (v >= speed) {
        break;
      }

      N++;
    }

    cout << N << endl;
  }

  return 0;
}

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

int main()
{
    double x;
    while (cin >> x) {
        double v = 0;
        int n = 1;
        while (v < x) {
            int f = 5 * n;
            double t = sqrt(f / 4.9);
            v = 9.8 * t;
            n++;
        }
        cout << n << endl;
    }
    return 0;
}

C++: #include<iostream>
#include<math.h>
using namespace std;
int main(){
  double v;
  while(cin >>v){
    double n=1;
    while(sqrt((n*5-5)/4.9)*9.8<v) n++;
    cout << n << endl;
  } 

  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
using ld = long double;
const ld eps = 1e-8;

int main()
{
	ld v;
	while (cin >> v) {
		for (int i = 1;; i++) {
			if (v * v / 19.6 - eps <= 5 * i - 5) {
				cout << i << endl;
				break;
			}
		}
	}
	return 0;
}

C++: #include <iostream>
using namespace std;
int main() {
	double v;
	while(cin >> v && v){
		double t;
		int h;
		t = v/9.8;
		for(int i=0; ; ++i){
			if(4.9*t*t <= 5*i-5){
				h = i;
				break;
			}
		}
		cout << h << endl;
	}
}

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

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

C++: #include<bits/stdc++.h>
#define rep(i,n)for(ll i=0;i<n;i++)
using namespace std;
typedef long long ll;

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

C++: #include <cstdio>
#include <cstdlib>
#include <iostream>
#include <string>
#include <cmath>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>

using namespace std;

int main(){
    double in,ans;
    
    while(scanf("%lf",&in)!=EOF){
        ans=pow(in/9.8,2)*4.9/5+1;
        printf("%.0lf\n",ans);
    }
    
    return 0;
}

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

#define floor(x) (x*5-5)

double t;

int   main()
{
	while (cin >> t)
	{
		double s;
		s = t * t / (2 * 9.8);
		
		s=(s + 5) / 5;
		s += 0.9;
		cout << int(s) << endl;
	}
	return 0;
}

C++: #include<iostream>
using namespace std;
int main()
{
long double v,n;
int N;
while(cin>>v)
{
n=(4.9*((v/9.8)*(v/9.8)))/5+1;
N=n*1000000;	
if(N%1000000==0)
{
	cout<<N/1000000<<endl;
}
else if(N%1000000!=0)
{
	cout<<N/1000000+1<<endl;
}
}
return 0;
}
//t=v/9.8 y=4.9*t*t N=y/5+1

C++: #include<iostream>
#include<string>
using namespace std;
int main(){
	double n;
	while(scanf("%lf",&n)!=EOF){
	for(int i=1;i<=10009;i++){
	int y=i*5-5;
	double t=sqrt((double)y/4.9);
	if(t*9.8>=n){cout<<i<<endl;break;}
	}
	}
	return 0;
}

C++: #include <iostream>
#include <string>
using namespace std;
int main(){
    double x;
	while(cin>>x){
	int i=1;
	while(true){
		if(i>1+x*x/98)
			break;
		i++;
	}
	cout<<i<<endl;
	}
	return 0;
}

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

int main(void)
{
  double y, v, t;
  double N;
  
  while(cin >> v) {
    t = v / 9.8;
    y = 4.9 * t * t;
    
    N =  y / 5 + 1 + 0.5;

    printf("%.0f\n", N);
  }
  return 0;
}

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

int main(){
  double v, time, y, height;

  while(scanf("%lf", &v) != EOF){
    time = v / 9.8;
    y = 4.9 * time * time;
    height = (y + 5) / 5;

    if(height > int(height)){
      height = int(height) + 1;
    }

    printf("%d\n", int(height));
  }

  return 0;
}

C++: #include<iostream>
#include<string>
#include<algorithm>
#include<map>
#include<set>
#include<utility>
#include<vector>
#include<cmath>
#include<cstring>
#include<cstdio>
#define loop(i,a,b) for(int i=a;i<b;i++) 
#define rep(i,a) loop(i,0,a)
#define rp(a) while(a--)
#define pb push_back
#define mp make_pair
#define all(in) in.begin(),in.end()
const double PI=acos(-1);
const double EPS=1e-10;
using namespace std;
typedef long long ll;
typedef vector<int> vi;
int main(){
	double n;
	while(cin>>n){
		double t=n/9.8;
		double y=t*t*4.9;
		int ans=1;
		while(5*ans-5<y)ans++;
		cout<<ans<<endl;
	}
}