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 <cstdio>
#include <iostream>

using namespace std;

int main() {
	double v;
	while (scanf("%lf", &v) != EOF) {
		printf ("%lld\n", (long long)((v * v / 19.6 + 5) / 5.0 + 0.5));
	}
	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 = 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>
#define rep(i, a, n) for(int i = a; i < n; i++)
using namespace std;

int main(){
    double v;
    while(cin >> v){
        double t = v / 9.8;
        double y = t * t * 4.9;
        int ans = 0;
        rep(i, 0, 60){
            int h = 5 * (i - 1);
            if(h > y){
                ans = i;
                break;
            }
        }
        cout << ans << endl;
    }
}

C++: //include----------------------------------------------------------------------------------------------------------------------
#include <bits/stdc++.h>

//using namespace--------------------------------------------------------------------------------------------------------------
using namespace std;

//define-----------------------------------------------------------------------------------------------------------------------
#define rep(i, n) for(int i = 0; i < n; i++)
#define FOR(i, s, n) for(int i = s; i < n; i++)
#define per(i, n) for(int i = n; i >= 0; i--)
#define ROF(i, s, n) for(int i = s; i >= n; i--)
#define FORIT(i, A) for (auto i : A)
#define PRINT(x) cout << (x) << endl
#define ALL(a)  (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define FOREACH(i, n) for (__typeof((n).begin()) i = (n).begin(); i != (n).end(); ++i)
#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())
#define INF 1 << 25
#define CLR(a) memset((a), 0 ,sizeof(a))
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;
#define sq(n) (n) * (n)

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

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

//global-----------------------------------------------------------------------------------------------------------------------
double a;
double test;

//function---------------------------------------------------------------------------------------------------------------------
void main() {
	while ( scanf( "%lf", &a ) != EOF ) {
		for ( int i = 1;; i++ ) {
			test = ( i * 5 - 5 ) / 4.9;
			test = sqrt( test );
			if ( test * 9.8 >= a ) {
				printf( "%d\n", i );
				break;
			}
		}
	}
}

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

int main(void)
{
	double v, times, hight, street;

	while (cin >> v) {
		times = v / 9.8;
		hight = 4.9 * times * times;
		street = (hight + 5.0) / 5.0;
		printf("%.0f\n", street);
	}
	
	return 0;
}

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

#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define REP(i, n) for (int i = 0; i < (n); i++)
#define RREP(i, n) for (int i = (n) - 1; i >= 0; i--)
#define sz(obj) ((int)(obj).size())
#define pf push_front
#define pb push_back

int main()
{
  double v, y, floor;

  while (cin >> v){
    int t = 0;
    while (9.8 * t < v) t++;
    y = 4.9 * t * t;
    floor = (y - 5) / 5;
    printf("%.0f\n", floor);
  }
}

C++: #include<stdio.h>
#include<iomanip>
#include<iostream>
#include<math.h>
#include<string.h>
#include<algorithm>
using namespace std;

int main()
{
    double v,t,a,x;
    a=9.8;
    while(cin>>v)
    {
        t= v/a;
        x=(a* pow(t,2))*.5;


        int result=0;
        result=(int)x/5;
        int y=x;
        if(y<x)
        result++;

        cout<<result+1<<endl;
    }
        return 0;
}

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

double speed(double time){
    return 9.8*time;
}
double height(double time){
    return 4.9*time*time;
}
double time(double speed){
    return speed/9.8;
}
int floor1(double height1){
    return static_cast<int>((height1+5)/5+0.5);
}

int main (int argc, char const* argv[]){
    double minspeed;
    double reachedTime;
    double heigh;
    
    while(cin >> minspeed){
        reachedTime = time(minspeed);
        heigh = height(reachedTime);
        cout << floor1(heigh)<< endl;
    }
    
    return 0;
}

/*
    m/s
*/

C++: #include <bits/stdc++.h>

using namespace std;

#define FOR(i, j, k) for(int i = j; i < k; ++i)
#define rep(i, j) FOR(i, 0, j)
#define repr(i, j) for(int i = j; i >= 0; --i)
#define INF (1 << 30)
#define MOD 1e9 + 7

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> P;

int num[5000];

int main() {
	double v;
	while(scanf("%lf", &v) != EOF) {
		double t = v / 9.8;
		double y = 4.9 * t * t;
		double N = (y + 5.0) / 5.0;
		double tmp = N * 10.0;
		int a = (int)tmp;
		if(a % 10 == 0) printf("%d\n", a / 10);
		else printf("%d\n", a / 10 + 1);
	}
	return 0;
}

C++: #include<bits/stdc++.h>
#include<vector>
#include<list>
#include<stack>
#include<queue>
#include<algorithm>
using namespace std;

int main(){
    int mod=1000000007;
    int n;
    int ans;
    double v;
    while (scanf("%lf",&v)!=EOF) {
        for (int i=0;;i++) {
            double t=v/9.8;
            double y=t*t*4.9;
            n=(int)floor((y+5.0)/5.0);
            for (int j=1;;j++) {
                if (j*5-5>=y) {
                    break;
                }
                tmp+=1;
            }
            printf("%d\n",j);
        }
    }
    return 0;
}

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

C++: #include <stdio.h>
#include <math.h>
int main(){
double v;
while(scanf("%lf",&v) != EOF){
double y=v*v/19.6;
int z=y;
if(y==z){
if(z%5==0){
	z=y/5+1;
printf("%d\n",z);
continue;
}
}
int q=y/5;
q += 2;
printf("%d\n",q);
}
return 0;
}

C++: #include <iostream>

using namespace std;

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

int main()
{
	solve();
	return(0);
}

C++: #include <bits/stdc++.h>

using namespace std;

int main(void) {
  double v;
  while (cin >> v) {
    int n = 0;
    while (n - v * v / (19.6 * 5) - 1.0 < -1e-10) {
      n++;
    }
    cout << n << endl;
  }

  return 0;
}

C++: #include<iostream>
using namespace std;
int main(){
  double a;
  int N;  
  while(cin>>a){
  N=(int)((a/9.8)*(a/9.8)*4.9+5)/5+1;
  cout<<N<<endl;
  }
  return 0;
}

C++: #include<stdio.h>

int main()
{
	int n;
	double v,y;
	while(scanf("%lf",&v) !=EOF)
	{
		y=(v/2.0)*(v/9.8);
		n=(y+5)/5;
		printf("%d\n",n);
	}
	return 0;
}