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++: //include
//------------------------------------------
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>

using namespace std;

//conversion
//------------------------------------------
inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}

//math
//-------------------------------------------
template<class T> inline T sqr(T x) {return x*x;}

//typedef
//------------------------------------------
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef long long LL;
typedef unsigned long long ULL;

//container util
//------------------------------------------
#define ALL(a)  (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EACH(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort((c).begin(),(c).end())

//repetition
//------------------------------------------
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)

//constant
//--------------------------------------------
const double EPS = 1e-10;
const double PI  = acos(-1.0);

//clear memory
#define CLR(a) memset((a), 0 ,sizeof(a))

//debug
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;

int main() {
  int n;
  double y, v, t;

  while(cin >> v) {
    t = v/9.8;
    y = 4.9 * t * t;

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

C++: #include<iostream>
#include<cmath>
using namespace std;
int fl(double v){
    double y=v*v/19.6;
    return 1+(int)(y+5)/5;
}
int main(){
    double v;
    while(cin>>v){
        cout<<fl(v)<<endl;
    }
    return 0;
}

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

int main(void){
	
	while (true){
		double v,t,y;
		cin>>v;
		if (cin.eof()) break;
		t = v/9.8;
		y = v/2*t;
		int h = ceil(y/5)+1;
		cout<<h<<endl;
	}
	return 0;
}

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

const int INF = 1e+9 * 2;
double eps = 1e-10;

int main() {
	long double v;
	while(cin >> v){
		double y = 4.9 * pow(v / 9.8, 2.0);
		for(int i = 1; ; ++i){
			if(5 * i - 5 >= y){
				cout << i << endl;
				break;
			}
		}
	}
	return 0;
}

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

main(){
  double V;
  while( cin >> V ){
    int N = (int)ceil((V*V*4.9/(9.8*9.8)+5)/5.0);
    cout << N << endl;
  }
}

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

int main(){
	double v,h;
	while(scanf("%lf",&v)!=EOF){
		int n=1;
		h=v*v/19.6;
		while(1){
			if(5*n-5>h) break;
			n++;
		}
		cout<<n<<endl;
	}
}

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

int main() {
  double x;
  while(cin >> x) {
    double y;
    y=4.9*((x/9.8)*(x/9.8));
    cout << ceil(y/5)+1 << endl;
  }
  return 0;
}

C++: #include <iostream>

using namespace std;

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

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

int main()
{
	double v;
	while(cin>>v)
	{
		double h=v*v/(2*9.8);
		int n=ceil((double)(h+5)/5);
		if(h==0)
		  cout<<"0"<<endl;
		else
		  cout<<n<<endl;
	} 
 return 0;
}

C++: #include<stdio.h>
#include<math.h>
#include<algorithm>
#include<cstring>
using namespace std;
//long long int arr[1000000];
int main()
{
    int a;
    double v,b;
   while(scanf("%lf",&v)==1)
   {
       v/=9.8;
       v=((v*v)*4.90)/5+1;
       a=v;
       b=v-a;
       if(b<0)
       printf("%d\n",a);
       else
       printf("%d\n",a+1);
   }
   return 0;
}

C++: #include<cstdio>
using namespace std;
int main()
{
    int n,i,res;
    double t,v,h;
    while(scanf("%lf", &v)==1)
    {
        t=(v/9.8);
        h=4.9*t*t;
        for(n=1;;n++)
        {
            res=5*n-5;
            if(res>h)
                break;
        }
        printf("%d\n",n);
    }
    return 0;
}

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

int main()
{
    for (double v; cin >> v;)
        cout << ceil((4.9 * v * v / 9.8 / 9.8 + 5) / 5) << endl;

    return 0;
}

C++: //#define _USE_MATH_DEFINES
#include <cmath>
#include <iostream>
//#include <stdio.h>
//#include <stdlib.h>
//#include <iomanip>
#include <vector>
//#include <string>
//#include <algorithm>
//#include <functional>
//#include <time.h>
//#include <sstream>
//#include <queue>

using namespace std;


int main(){

	const int H = 5;
	double v, t, y;
	long long ans;

	while (cin >> v){
		t = v / 9.8;
		y = 4.9 * t * t;
		ans = (long long)(ceil(y / H)+1);
		cout << ans << endl;
	}


	return 0;
}

C++: #include<iostream>
using namespace std;
int main(){
  double a,b,c;
  while(cin>>a){
    b=0;int s=0; 
    while(1){if(9.8*b>=a)break;b+=0.000001;}
    while(1){
      if(4.9*b*b<=s)break;
      s+=5;
    }cout<<s/5+1<<endl;
  }
}

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

int main(){
	double mv;
	while (cin >> mv)
		cout << ceil((mv*mv / (9.8f * 2)) / 5 + 1) << endl;
}

C++: #include <iostream>
#include <iomanip>
#include <math.h>
#include <utility>
#include <vector>
#include <cstdlib>
#include <algorithm>
#include <climits>
using namespace std;

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

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

int main(){
	double v;
	while( scanf("%lf",&v)!=EOF){
		v=ceil((v*v/19.6+5)/5);
		printf("%d\n",(int)v);
	}
			
	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 i=1;
		while(1){
			double h = 5 * i - 5;
			if(y <= h) break;
			i++;
		}
		cout << i << endl;
	}
	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
int main(void){
	double v,t;
	double y;
	int ans;
	while(1){
		cin>>v;
		if(cin.eof()==1)	break;
		t=v/9.8;
		y=4.9*pow(t,2);
		y+=5;
		if(fmod(y,5.0)!=0){
			y/=5;
			y++;
		}
		else	y/=5;
		ans=y;
		cout<<ans<<endl;
	}
	return 0;
}

C++: 
#include<iostream>
#include<stdio.h>

using namespace std;

int main(){
	double  v;

	while(scanf("%lf",&v) != EOF){

		cout << (int)((49*2*v*v)/(98*98) + 1 + 0.9) << endl;
	}
	return 0;
}

C++: #include <cmath>
#include <iostream>
#define	GA	9.8

int main() {
	double v;
	double y;
	int n;
	while (std::cin >> v) {
		y = v * v / (2. * GA);
		n = ceil((y + 5.) / 5.);
		std::cout << n << '\n';
	}
	return 0;
}

C++: #include <iostream>
using namespace std;
int main()
{
    double v, y, t, f, n;
    long long int i, a;
    while(cin>>v)
    {
        t=v/9.8;
        //cout<<t<<endl;
        y=4.9*t*t;
        for(i=1;;i++)
        {
            f=i*5-5;
            if(f>=y)
            {
                a=i;
                break;
            }
        }
        cout<<a<<endl;
    }
}