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 <iostream>
#include <queue>
#include <stack>
#include <vector>
#include <stdio.h>
#include <algorithm>
#include <string.h>
#include <string>
using namespace std;

#define rep(i,n) for(int i=0;i<int(n);++i)


double v,y,t;
int n;


int main(){
	
	
	while(cin>>v){
		t = v/9.8;
		y = 4.9*t*t;
		rep(i,1000000){
			if(5*i-5>=y){
				n = i;
				break;
			}
		}
		cout<<n<<endl;
	}
	return 0;
}

C++: #ifndef _GLIBCXX_NO_ASSERT
#include <cassert>
#endif
#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>

#ifdef __GXX_EXPERIMENTAL_CXX0X__
#include <ccomplex>
#include <cfenv>
#include <cinttypes>
#include <cstdbool>
#include <cstdint>
#include <ctgmath>
#include <cwchar>
#include <cwctype>
#endif

#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>

#ifdef __GXX_EXPERIMENTAL_CXX0X__
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#endif

#include <array>

using namespace std;

int main ()
{
	double x;
	while( cin >> x )
	{
		cout <<(int) ( pow ( x  , 2.0 )/(2*9.8) + 5 +5-(1e-19)) / 5 << endl;
	}
}

C++: #include <iostream>
using namespace std;
int main(void){
    double v;
    double t; //球が割れるのに必要な最低速度になるのは落下し始めてから何秒後か
    int y; //t秒後に物体が落下した距離
    int N; //球が割れる建物の階の最小値

    while(cin >> v){
        t = v / 9.8;
        y = 4.9 * t * t;
        N = ((y + 1) + 5) / 5; 

        cout << N + 1<< endl;
    }
}

C++: #include<iostream>

int main(){

	double min_v;
	while (std::cin >> min_v){

		double t = min_v / 9.8;
		double sum = 4.9*t*t;

		std::cout << (int)(sum + 5) / 5 + 1 << std::endl;
	}

	return 0;
}

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

using namespace std;

int main(int argc, char *argv[]) {
  vector<int> result;
  double v, t, h;

  while (cin >> v) {
    t = v / 9.8;
    h = 4.9 * t * t;
    int n = 1;
    while (true)
      if (5 * (n - 1) >= h) {
        result.push_back(n);
        break;
      } else {
        n++;
      }
  }

  for (int i = 0; i < result.size(); i++)
    cout << result[i] << endl;
  return 0;
}

C++: #include<iostream>
#include<cstdio>
#include<cmath>
using namespace std;
#define int long long
signed main(){
	double a;
	while( scanf("%lf", &a) != EOF ){
		double y = a*a/2/9.8;
		int n = y/5 + 2;
		cout << n << endl;
	}
	return 0;
}

C++: #include <iostream>
#include <algorithm>
using namespace std;
int main(){
	double v,y;
	int n;
	while(cin>>v){
		n=(((v*v/19.6)+5)/5)+1;
		cout<<n<<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){
		if (v <= 0) ans = 1;
		else{
			t = v / 9.8;
			y = 4.9 * t * t;
			ans = (long long)((y + 10 + 1) / H);
		}
		cout << ans << endl;
	}


	return 0;
}

C++: #include <iostream>
int main(){for(double v;std::cin>>v;)std::cout<<(int)(v*v/19.6+10)/5<<"\n";}

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

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

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

int main()
{
double a;
while(~scanf("%lf",&a))
{
int ans=ceil(a*a/98)+1;
printf("%d\n",ans);
}
return 0;
}

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

int main(){

  int n;
  double v,t,y;

  while(cin >> v){

    t = v/9.8;
    y = 4.9 * t * t;

    int i = 0;

    while(5*i-5 < y) i++;

    cout << i << endl;
  }
}

C++: //0024 Physical Experiments

// élª¢Êu©çKXð©Rº³¹é
//v=9.8tAy=4.9t^2ÆÈé
//ªêéÌÉKvÈÅá¬xª^¦çêéÆ«A­È­ÆàrÌ½K©çÆ¹Îæ¢©
//½¾µArÌNKÌ³Í5N-5Æ·é

#include<iostream>
#include<cmath>
using namespace std;
double Square(double x){return x*x;}
int main(void)
{
	double y, v, t;
	while(cin >> v)
	{
		t = v/9.8;
		y = 4.9*Square(t);
		//y >= 5N-5
		//N <= y/5+1
		int N = static_cast<int>(ceil(y/5.0+1.0));
		cout << N << endl;
	}
	return 0;
}

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

int main()
{
    int y, t, v, nv, cont = 1;
    cin >> nv;
    
    y = (nv * nv) /19.6;

    while(y>0){	
	y -= 5;
	cont++;
    }
    
    cout << cont << endl;
    
}