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 <string>
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(true){
        if (5 * n - 5 >= y){
            cout << n << endl;
            break;
        } else {
            n++;
        }
        }
    }
 
    return 0;
}

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

main(){
  double V;
  while( cin >> V ){
    int N = (int)ceil((V*V*4.9/(9.8*9.8)+5)/5.0 + 0.000000001);
    cout << N << endl;
  }
}

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

int main() {
	double v;
	double t, y;
	long long n;
	
	while( cin >> v ){
		t = v / 9.8;
		y = 4.9 * t * t;
		n = (y + 5.0 - 1e-12) / 5 + 1;
		cout << n << endl;
	}
	return 0;
}

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

int main(){
	double d,y;
	int res;
	while(cin>>d){
		y=d*d/19.6;
		cout<<y<<endl;//debug
		res=ceil(y);
		res=max((res-1)/5+2,1);
		cout<<res<<endl;
	}
	return 0;
}

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

using namespace std;

int main() {
	float v;
	while (scanf("%f", &v) != EOF) {//精度&#38382;&#39064; 
		printf ("%d\n", (int)ceil((v * v / 19.6 + 5) / 5.0 + 0.000000001));
	}
	return 0;
}

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

int main(void) {
    double speed;
    while(cin >> speed) {
        double y = (speed / 2.0) * (speed / 9.8);
        double n = (y + 5) / 5.0;
        cout << ceil(n) << endl;
    }
    return(0);
}

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

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

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

int main(){
	
	double n;
	
	while(scanf("%lf",&n)!=EOF){
		n=n/9.8;
		n=n*n*4.9;
		int i;
		for(i=1;i*5-5<n;i++);
		cout<<i<<endl;
	}
	return 0;
}

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

int main(void)
{
    double n;
    while(cin >> n) {
        for (int i = 1; i < 1000; ++i) {
            double h = 5 * i - 5;
            double t = sqrt(h / 4.9);
            double v = 9.8 * t;
            if (v >= n) {
                cout << i << endl;
                break;
            }
        }
    }
    return 0;
}

C++: #include<iostream>
using namespace std;
int main(){
	double v0,t;
	while(cin>>v0){
		int n=0;
		t=0;
		t=v0/9.8;
		while(5*n-5<=4.9*t*t){
			n++;
		}
		cout<<n<<endl;
	}
}

C++: #include<algorithm>
#include<functional>
#include<cmath>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<string>
#include<sstream>
#include<iostream>
#include<iomanip>
#include<vector>
#include<list>
#include<stack>
#include<queue>
#include<map>
#include<set>
#include<bitset>

#define all(c) (c).begin(), (c).end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define pb(e) push_back(e)
#define mp(a, b) make_pair(a, b)
#define fr first
#define sc second

typedef unsigned long long ull;
typedef long long ll;

const int INF=100000000;
int dx[4]={1,0,-1,0};
int dy[4]={0,1,0,-1};

using namespace std;

typedef pair<int ,int > P;

double v;

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

		int ans=1;
		while(ans*5-5<y)
			ans++;
		cout<<ans<<endl;

	}


	return 0;
}

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

int main(){
	double v, y;
	while(cin >> v){
	y = 4.9 * pow(v / 9.8, 2);
	int n;
	for(n = 0;;n++){
		if(y <= 5*n-5)break;
	}
	cout << n << endl;
	}
	return 0; 
}
//25.4
//32

C++: #include <iostream>
#include <sstream>
#include <string>
#include <vector>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <ctime>
using namespace std;

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

#define all(c) (c).begin(), (c).end()
#define pb push_back
#define mp make_pair
#define EXIST(v,i) (find(all(v), i) != (v).end())
#define ERASE(v,i) (v).erase(remove(all(v), i), (v).end())
#define INDEX(v,i) (find(all(v), i) - (v).begin())
#define rep(i,n) for(int i = 0; i < (int)n; ++i)
#define debug(x) cerr << #x << " = " << (x) << endl;

inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}

const int INF = 100000000;
const double PI = 3.14159265358979323846;
const double EPS = 1e-10;

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

C++: #include<iostream>
using namespace std; 
int main(){
  double v,y;
  while(cin>>v){
    y=v*v/19.8/5+2;
    cout<<(int)y<<endl;
  }
}

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

using namespace std;

#define EPS (1e-10)
#define EQ(a,b) (abs((a) - (b)) < EPS)

int main(){

	double v;

	while(cin>>v){
		double t = v/9.8;
		double y = 4.9*t*t;
		if(EQ(y,0))
			cout<<1<<endl;
		else
			cout<<(int)(y/5)+2<<endl;
	}
		
	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,a) FOR(i,0,a)

int main(){
	ios::sync_with_stdio(false);
	double v;
	while (cin>>v){
		int N;
		for (N=2;;N++){
			double t;
			t=sqrt((5*N-5)/4.9);
			if (9.8*t>=v){
				break;
			}
		}
		cout<<N<<endl;
	}
	return 0;
}

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

typedef pair<double,double>vec;

int main()
{
    double v;
    while(cin>>v){
        double h=4.9*(v/9.8)*(v/9.8);
        int ans=0;
        for(;5*ans-5<h;ans++){}
        cout<<ans<<endl;;
    }
    return 0;
}

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 vn, yn, out, tn;

int main()
{
	
	while( cin >> vn, !cin.eof())
	{
		tn = vn/9.8;
		
		yn = pow(tn, 2) * 4.9;
		
		for( int i = 1; i < INT_MAX; i++)
		{
			int f = 0;
			double flr = (double)(i-1)*5.0;
			
			if( flr >= yn )
			{
				cout << i << endl;
				f = 1;
				break;
			}
			
			if(f)
				break;
		}
		
	}
	
	return 0;
}

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

int main() {
	double v,y;
	int n;
	while (cin >> v) {
		y = v*v / 19.6;
		n = (y-0.0000000001) / 5;
		cout << n+2 << endl;
	}
	return 0;
}

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 <cmath>
#include <cstdio>
#include <cstdlib>

using namespace std;

int main() {
  char *line = NULL;
  size_t buffer_size = 0;
  while (getline(&line, &buffer_size, stdin) > 0) {
    double required_velocity;
    sscanf(line, "%lf", &required_velocity);
    double required_time = required_velocity / 9.8;
    double required_height = 4.9 * required_time * required_time;
    double required_floor = ceil(required_height / 5.0) + 1.0;
    printf("%.0f\n", required_floor);
  }
  free(line);

  return 0;
}