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
			ans := (x+5)/5+1
			fmt.Printf("%d\n", int(ans))
	}
}

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

using namespace std;

int main(){
	double  v;

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

		cout << (int)((4.9/5)*((v*v)/(9.8*9.8)) + 1 + 0.9)<< endl;
	}
	return 0;
}

C++: #include <iostream>

using namespace std;

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

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 = (y + 5) / 5 + 1;
	cout << N << endl;
  }
  
  return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <cstring>
#include <sstream>
#include <algorithm>
#include <math.h>
#include <map>
#include <functional>
#include <iomanip>
#include <vector>
#include <queue>
#include <stack>
#include <set>
#include <typeinfo>
#define PI 3.14159265359
#define INF 99999999
#define rep(i, n) for(int i=0; i<n; i++)
#define REP(n) rep(i, n)
#define EPS 1e-10
#define pb push_back
#define mp make_pair
typedef long long ll;
using namespace std;
typedef pair<int, int> P;

double v;

int main()
{
	while (cin >> v)
	{
		int ans = 1.0 * v * v / (5 * 19.6) + 1.0;
		cout << ans + 1 << endl;
	}
	
	return 0;
}

C++: #include<iostream>
using namespace std;
int main(){
	double v;
	int y;
	while(cin>>v){
		y=(v/9.8)*(v/9.8)*4.9;
		if(y%5==0)cout<<y/5+1<<endl;
		else cout<<y/5+2<<endl;
	}
}

C++: #include <cstdio>
int main()
{
    float v,h;
    float i=1;
    while(~scanf("%f",&v))
    {
        h=v*v/(9.8*2);
        while(1)
        {
            if((i-1)*5>=h)
            break;
            i++;
        }
        int j=(int)i;
        printf("%d\n",j);
    }
    return 0;
}

C++: #include "stdafx.h"
#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;
	while (cin >> v) {
		n = 1;
		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()
{
	int i;
	double n,v,y;
	
	for(;cin >> n;)
	{
		v=double(n)/9.8;
		y=4.9*v*v;
		for(i=1;5*(i-1)<y;i++)
		{}
		cout << i << endl;
	}
}

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

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

      double temp = ((y + 5) / 5);
      int intemp = (int)temp;
      double dotemp = temp - intemp;
      if( 1 > dotemp && dotemp > 0 ) ++intemp;
      cout << intemp << endl;
   }
}

C++: /*****include*****/
#include <iostream>
#include <fstream>
#include <string>

/*****デバッグ定義*****/
//#define DEBUG
/*****マクロ定義*****/

/*****名前空間*****/
using namespace std;

/*****グローバル変数置き場*****/

/*****その他関数置き場*****/

/*****main関数*****/
int main(){
	/*****ファイルオープン*****/
#ifdef DEBUG
	ofstream fout("output.txt");
	ifstream fin("input.txt");
	if(!fout || !fin){
		cout << "Can't open the file.\n";
		return;
	}
#endif
	/*****変数置き場*****/
	double b_v;
	double v_sq;
	long int n;
	/*****処理部*****/
	while(1){
		scanf("%d",&b_v);
		if(b_v == 0)	break;
		n=0;
		v_sq = 0;
		while(v_sq < b_v*b_v){
			n++;
			v_sq = 19.6 * (5*(double)n - 5);
		}
		printf("\n%d",n);
	}
	/*****処理終了後*****/
#ifdef DEBUG
	fout.close();
	fin.close();
#endif
	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;
	int ans;

	while (cin >> v){
		if (v == 0) ans = 1;
		else{
			t = v / 9.8;
			y = 4.9 * t * t;
			ans = (int)((y + 10 + 1) / H);
		}
		cout << ans << endl;
	}


	return 0;
}

C++: /*
 * Problem: AOJ0024
 * Author: YOUSIKI
 * Date: 2016/6/23
 */
#include<bits/stdc++.h>
using namespace std;
signed main(void){
	ios::sync_with_stdio(false);
	double input;
	while(cin>>input){
		/*
		 * v=9.8*t
		 * y=4.9*t^2
		 * so y=4.9*(v/9.8)^2
		 *     =v^2/(9.8*2)
		 * but y must can be written into a form like
		 *     5*(n-1)
		 * so we have to find the min(n-1) to make y>=5*(n-1)
		 * and it's surely ceil(y/5)
		 */
		cout<<ceil(pow(input,2)/(9.8*2.0)/5.0+1.0)<<endl;
	}
}

C++: #include <iostream>
#include <cmath>
using namespace std;
int main( void )
{
  double d;
  while( 1 ){
    cin >> d;
    if( cin.eof() ) break;
    d = d*d / (2*9.8);
    cout << (int)ceil(d/5) + 1 << endl;
  }
  return 0;
}

C++: #include<iostream>
using namespace std;
int main()
{
long double v,n;
int N;
while(cin>>v)
{
n=0;
N=0;
n=(4.9*(v/9.8)*(v/9.8))/5+1;
N=n*10;	
if(N%10==0)
{
	cout<<N/10<<endl;
}
else if(N%10!=0)
{
	cout<<N/10+1<<endl;
}
}
return 0;
}

C++: #include<cstdio>

using namespace std;

int main()
{
	double v,t,y;
	int n,h[100000];

	for(int i=0;i<100000;i++){
		h[i]=i*5-5;
	}

	while(scanf("%lf",&v)!=EOF){
		t=v/9.8;
		y=4.9*t*t;
		n=(int)((y+5.0)/5.0);
		for(int i=0;i<100000;i++){
			if(h[i]>=y){
				n=i;
				break;
			}
		}
		printf("%d\n",n);
	}
	return 0;
}

C++: #include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <cmath>
#include <cstdio>
#include <functional>
#include <numeric>
#include <stack>
using namespace std;

#define FOR(i,a,b) for(long long int i=(a);i<(b);i++)
#define REP(i,n) for(long long int i=0;i<(n);i++)
#define ALL(s) (s).begin(),(s).end()

#define PI 3.14159265358479

typedef long long ll;
typedef vector<long long int> vi;
typedef vector<long long int>::iterator vit;

int main(){
	double v;
	while (cin >> v){
		for (int i = 0;;i++){
			if (v < 9.8*sqrt((5 * i - 5) / 4.9)){
				cout << i << "\n";
				break;
			}
		}
	}
}

C++: #define _USE_MATH_DEFINES

#include <iostream>
#include <string>
#include <sstream>
#include <iomanip>
#include <cmath>
#include <algorithm>
#include <utility>
#include <vector>
#include <numeric>

using namespace std;

int main()
{
	double v;
	for (; cin >> v;)
	{
		double y = 4.9 * pow(v / 9.8, 2);

		cout << (int)(y / 5 + 2) << endl;
	}
}

C++: #include<iostream>
#include<algorithm>
#include<vector>
#include<stack>
#include<queue>
#include<cstdio>
#include<climits>
#include<cmath>
#include<cstring>
#include<string>
#include<complex>

#define f first
#define s second
#define mp make_pair

#define REP(i,n) for(int i=0; i<(int)(n); i++)
#define FOR(i,c) for(__typeof((c).begin()) i=(c).begin(); i!=(c).end(); i++)
#define ALL(c) (c).begin(), (c).end()
#define EPS (1e-10)
using namespace std;

typedef unsigned int uint;
typedef long long ll;
typedef complex<double> P;

int main(){
  double v;
  while(cin>>v){
    for(int n=0; ; n++){
      double h = n*5;
      double tmp = 9.8 * sqrt( h / 4.9 );
      if(tmp >= v){
	cout << n+1 << endl;
	break;
      }
    }
  }
  return 0;
}

C++: #include <stdio.h>
#include <math.h>
typedef long double ld;
int main(){
	ld v;
	while(scanf("%Lf",&v)!=EOF){
		ld t=v/9.8;
		ld h=4.9*t*t;
		int n=ceil(h/5.0)+1.0;
		printf("%d\n",n);
	}
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
using ld = long double;
const ld eps = 1e-12;

int main()
{
	ld v;
	while (cin >> v) {
		for (int i = 1;; i++) {
			if (v * v - eps <= 98 * i - 98) {
				cout << i << endl;
				break;
			}
		}
	}
	return 0;
}

C++: #include <iostream>
main(){for(double v;std::cin>>v;)std::cout<<(int)v*v/98+2<<"\n";}