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 <algorithm>
# include <vector>
# include <string>
# include <set>
# include <map>
# include <cmath>
# include <iomanip>
# include <functional>
# include <utility>
# include <stack>
# include <queue>
# include <list>
# include <bitset>
# include <complex>
# include <numeric>
using namespace std;
using LL = long long;
using ULL = unsigned long long;
constexpr long long MOD = 1000000000 + 7;
constexpr int INF = 2000000000;
constexpr int HINF = INF / 2;
constexpr double DINF = 100000000000000000.0;
constexpr long long LINF = 9223372036854775807;
constexpr long long HLINF = 4500000000000000000;
const double PI = acos(-1);

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

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

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 <iostream>

using namespace std;

int main() {
	double v;

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

		for (int i = 1; ; i++) {
			if (5 * i - 5 > v) {
				cout << i << endl;
				break;
			}
		}
	}
	return 0;
}

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

int main() {
	double v;
	while(cin >> v) {
		double y = v*v / 19.8;
		double N = (y+5.0) / 5.0;
		cout << ceil(N) << endl;
	}

	return 0;
}

C++: #include <iostream>
#include <string>
#include <algorithm>
#include <cstdio>
#include <vector>
#include <cmath>
#include <stack>
#define REP(i, n) for(int i = 0;i < n;i++)
#define REPR(i, n) for(int i = n;i >= 0;i--)
using namespace std;

int main(){
    double n;
    while (cin>>n){
        double t, y;
        t = n / 9.8;
        y = 4.9 * t * t;
        int N;
        N = y / 5 + 2;
        cout << N << endl;
    }
}

C++: #include "bits/stdc++.h"
using namespace std;
int main() {
	double v;
	while (cin >> v) {
		int N = 0;
		double V = 0;
		do{
			N++;
			double h = 5 * N - 5;
			V = 9.8*pow(h / 4.9, 0.5);
		} while (V < v);
		cout << N << endl;
	}
}

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

int main() {
  double v;
  while(cin >> v) {
    cout << (int)ceil(v*v/98.0)+1 << endl;
  }
  return 0;
}

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

int main(void) {
    double speed;
    while(cin >> speed) {
        double y = (speed / 2) * (speed / 9.8);
        double n = (y + 5) / 5.0;
        printf("%.0f\n", n);
    }
    return(0);
}

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

int main() {
  double v;
  while(cin >> v) {
    double N = v*v/98.0+1;
    if(N != (int)N) ++N;
    cout << (int)N << endl;
    //cout << (int)ceil(v*v/98.0+1) << endl;
  }
  return 0;
}

C++:  
 #include<iostream>
 #include<stdio.h>
 #include<string>
 #include<math.h>
 #include<iomanip>
 #include<algorithm>
 #include<string.h>
 #include<cctype>
 #include<map>
 #include<set>
 #include<vector>
 #include<sstream>
 #include<stack>
 
 using namespace std;
 
 double abs(double x)
 {
   if(x<0) return -x;
   else return x;       
 }
  
 int main()
 {
   int v;
   while(cin>>v)
   {
     double t=v/9.8;
     double h=4.9*t*t;
     int N=(int)((h+5)/5)+1;
     cout<<N<<endl;
   }
   //while(1);      
   return 0;    
 }

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

int main(){
	int n;
	while(cin >> n){
		n = n*n/19.6;
		n = (n+5)/5;
		cout << n <<"\n";
	}
	return 0;
}

C++: #include<stdio.h>
#include<iostream>
#include<list>
#include<map>
#include<vector>
#include<algorithm>
#include<string.h>
#define range(i,a,b) for(int i = (a); i < (b); i++)
#define rep(i,b) range(i,0,b)
#define debug(x) cout << x << endl;
using namespace std;

int main(){
    double input, time, height;

    while(cin >> input){
        time = input / 9.8;
        height = 4.9 * time * time;
        rep(i, 10000){
            if(height < 5 * i - 5){
                cout << i << endl;
                break;
            }
        }
    }
}

C++: 
#include <iostream>
#include <cstdlib>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <stack>
#include <cctype>
#include <complex>
#include <vector>
#include <algorithm>
#include <cassert>

using namespace std;


bool solve(){
	double in;
	while(cin>>in){
		int y = 4.9 * (in/9.8) * (in/9.8);
		int ans = 0;
		for(int i=1;i<10000;i++){
			int h = 5 * (i - 1);
			if(h > y){
				ans = i;
				break;
			}
		}
		cout<< ans<< endl;
	}
	return true;
}

int main(){
	cout.setf(ios::fixed);
	cout.precision(10);
	solve();

	return 0;
}

C++: #include <iostream>
#include <stdio.h>
using namespace std;
int main(){
  int nr;
  double v,n;
  while(scanf("%lf",&v)!=EOF){
    n=(v*v+98)/98;
    nr=n*10;
    if(nr%10!=0) cout << nr/10+1 << endl;
    else cout << nr/10 << endl;
  }
  return 0;
}

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



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

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
    double 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 + 5) / 5; 

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

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

typedef pair<double,double>vec;

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

C++: #include<stdio.h>
#include<math.h>
#include<limits.h>
int main()
{
	double V,y,v,t;
	while(scanf("%lf",&V)>0)
	{
		int l=0,r=INT_MAX,m;
		while(l<r)
		{
			m=(l+r)/2;
			y=5.*m-5;
			t=sqrt(y/4.9);
			v=9.8*t;
			if(V<=v)r=m;
			else l=m+1;
		}
		printf("%d\n",l);
	}
	return 0;
}