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 <algorithm>
#include <string>
#include <vector>
#include <stack>
#include <queue>
#include <cstring>
#include <climits>
#include <cmath>
#include <cfloat>

using namespace std;

double v, y, out, t;

int main()
{
	
	while( cin >> v, !cin.eof())
	{
		t = v/9.8;
		y = t*t*4.9;
		
		for( int i = 1; i < INT_MAX; i++)
		{
			int f = 0;
			double flr = (double)(i-1)*5.0;
			
			if( flr >= y )
			{
				cout << i << endl;
				f = 1;
				break;
			}
			
			if(f)
				break;
		}
		
	}
	
	return 0;
}

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;
		int n=(((y+5)/5)*10+9)/10;
		
		/*for(int i=0;0<y;i++){
			y-=5;
			c++;
		}*/
		cout<<n<<endl;
	}
}

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

using namespace std;

int main() {
	double crackSpeed;
	
	crackSpeed = -1;
	cin >> crackSpeed;
	
	while (crackSpeed >= 0) {
		
		double crackTime = crackSpeed / 9.8;
		double crackDist = 4.9 * crackTime * crackTime;
		
		int numFloor = 1;
		
		while ((double)(5 * numFloor - 5) < crackDist) numFloor++;
		
		cout << numFloor << endl;
		
		crackSpeed = -1;
		cin >> crackSpeed;
	}
	
	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;

int v;

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

C++: #include<iostream>
#include<cmath>
using namespace std;
int main()
{
	double v,y;
	while(cin>>v){
	y=4.9*v/9.8*v/9.8;
	for(int i=1;i<100;i++){
		if((i*5-5)>y){
			cout<<i<<endl;
		break;
		}
	}	
	}
}

C++: #define _USE_MATH_DEFINES
#include<iostream>
#include<iomanip>
#include<algorithm>
#include<cctype>
#include<cmath>
#include<cstdio>
#include<deque>
#include<list>
#include<set>
#include<stack>
#include<string>
#include<sstream>
#include<map>
#include<queue>
#include<vector>
using namespace std;

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

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

int main(){
	double 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<cstdio>
int main(){
    double s;
    while(~scanf("%lf",&s)){
        double y=(4.9*(s/9.8)*(s/9.8))+5;
        if(y==(int)(y/5)*5) printf("%d\n",(int)y/5);
        else printf("%d\n",(int)y/5+1);
    }
}

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

int main()
{
	double minv, v=0.0, y=0.0;
	double t, high = 0.0;
	int f=1;

	while (cin >> minv)
	{
		high = 0;
		t = minv / 9.8;
		y = 4.9 * t * t;
		for (f = 0; high <= y; f++)
		{
			high = f * 5 - 5;
		}
		if (high != y) f--;
		cout << f << endl;
	}
	return 0;
}

C++: #include<iostream>

using namespace std;



main(){
  double minv;
  while(cin >>minv){
    int i;
    double t = minv/9.8;
    double y;
    y = 4.9*t*t;
    double tall;
    for(i=1;y>=tall ; i++){
      tall = 5*i-5;
    }

    cout << --i << endl;


  }





  return 0;
}

C++: #include <iostream>

using namespace std;

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

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

// ?????¬???????????¬??????
#pragma region MACRO
#define P(x) cout << (x) << endl
#define p(x) cout << (x)
#define PED cout << "\n"
#define rep(i,n) for(int i=0; i<(int)n; ++i)
#define REP(i,x,n) for(int i=x; i<(int)n; ++i)
#define repi(i,n) for(int i=0; i<=(int)n; ++i)
#define REPI(i,x,n) for(int i=x; i<=(int)n; ++i)
#define ILP while(true)
#define FOR(i,c) for(__typeof((c).begin())!=(c).begin(); i!=(c).end(); ++i)
#define ALL(c) (c).begin(), (c).end()
#define mp make_pair
#pragma endregion

// ???
#pragma region TYPE_DEF
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<string, string> pss;
typedef pair<string, int> psi;
typedef pair<int, string> pis;
typedef vector<int> vi;
typedef vector<double> vd;
typedef vector<long double> vld;
typedef vector<long> vl;
typedef vector<long long> vll;
typedef vector<string> vs;
#pragma endregion

// Effective std
#pragma region ESTD
template<typename C, typename T> int count(C& c, T t) { return count(ALL(c), t); }
template<typename C, typename F> int count_if(C& c, F f) { return count_if(ALL(c), f); }
template<typename C, typename T> void erase(C& c, T t) { remove(ALL(c), t), c.end(); }
template<typename C> void remove(vector<C>& c, unsigned int index) { c.erase(c.begin()+index); }
template<typename C, typename T, typename U> void replace(C& c, T t, U u) { replace(ALL(c), t, u); }
template<typename C, typename F, typename U> void replace_if(C& c, F f, U u) { (ALL(c), f, u); }
template<typename C> void reverse(C& c) { reverse(ALL(c)); }
template<typename C> void sort(C& c) { sort(ALL(c)); }
template<typename C, typename Pred> void sort(C& c, Pred p) { sort(ALL(c), p); }
#pragma endregion

// ?????°
#pragma region CONST_VAL
constexpr int PI = (2*acos(0.0));
constexpr int EPS = (1e-9);
constexpr int MOD = (int)(1e9+7);
constexpr int INF = 100000000;
#pragma endregion


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

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

using namespace std;

int main()
{
    double v;

    while (scanf("%lf", &v) != EOF) {
        double ans = (v*v/98);
        if (ans - (int)ans < 0.000000001) {
            printf("%d\n", (int)ans + 1);
        } else {
            printf("%d\n", (int)ans + 2);
        }

    }

    return 0;
}

C++: #include<cstdio>
#include<cstring>
#include<algorithm>
#include<functional>
using namespace std;
int main(void)
{
	int i,j,y,cnt;
	double n,x,raka;
	while(scanf("%lf",&n)!=EOF) {
		cnt=1;
		x=n/9.8;
		raka=4.9*(x*x);
		i=1;
		while(1) {
			if(5*i-5<raka) cnt++;
			else break;
			i++;
		}
	}
	printf("%d\n",cnt);
	return 0;
}

C++: #include<iostream>
using namespace std;
int main(){
  double v,t,y;
  int sy;
  while(cin>>v){
    t=v/9.8;
    y=4.9*t*t;
    sy=0;
    while(1){
      if((5*sy-5)>y){
	break;
      }
      sy++;
    }
    cout<<sy<<endl;
  }
  return 0;
}

C++: #include <iostream>

using namespace std;

void storey(double);

int main() {

	double min;

	while(cin>>min) {
		storey(min);
	}

	return 0;

}

void storey(double min) {

	double t, y, N;

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

	N=y/5+1;
	N+=0.9;
	N=(int)N;

	cout << N << endl;

}

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

using namespace std;

int main(void)
{
	double input;
	while(cin>>input)
	{
		for(int i=0;;i++)
		{
			double t=sqrt((5*i-5)/4.9);
			if(9.8*t>input)
			{
				cout<<i<<endl;
				break;
			}
		}
	}
}