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>

using namespace std;

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

	while (1){
		cin >> v;
		y = (v*v) / 19.6;
		n = y / 5 + 2;
		cout << n;
	}

	return 0;

}

C++: #include <bits/stdc++.h>
#define PI 3.14159265359
using namespace std;

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

		int N = 1;
		while (1) {
			int height = 5 * N - 5;
			if (height >= y) {
				break;
			}
			else {
				N++;
			}
		}

		cout << N << endl;
	}
}

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

int main()
{
	double v;
	while ( cin>>v )
		cout << int(v*v/19.6/5)+2 << endl;
	return 0;
}

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

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

C++: #include <iostream>
#include <iomanip>
#include <vector>
#include <string>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <algorithm>
#include <sstream>
#include <cstdlib>
#include <cstring>
#include <functional>
#include <numeric>
#include <cmath>
#include <climits>
#include <limits>
#include <cfloat>
#include <fstream>
using namespace std;

int main()
{
//	cut here before submit 
//	freopen("testcase.dat", "r", stdin);
	string str = "";

	while (getline (cin, str ) ){
		int res = 0;
		double v;		
		stringstream ss(str);
		ss >> v;
		int n;

		for (n = 1;; ++n){
			int f = 5*(n-1) - 5;
			if ((double)f < v){
				continue;
			}else{
				res = n;
				break;
			} // end if
		} // end for

		cout << res << endl;
	} // end for

	return 0;
}

C++: #include <stdio.h>

int main(void){
	double N;
	double v;
	while(scanf("%lf",&v)!=EOF){
		N=v*v/(10.0*9.8)+1.0;
		printf("%d\n",(int)(N) + 1);
	}
	return 0;
}

C++: #include<iostream>
#include<stdio.h>
#include<math.h>
#include<string>
#include<queue>
#include<algorithm>
#include<utility>
#include<vector>
#include<list>
using namespace std;
int main() {
	double t, v, y,n,in;
	while (cin >> v) {
		t = v / 9.8;
		y = 4.9*pow(t, 2);
		n = (y + 5) / 5;
		in = (int)n;
		if (in == n)cout << n << endl;
		else cout << (int)n+1 << endl;
	}
	return 0;
}

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

int main(){
	float mv;

	while (cin >> mv)
		cout << ceil((mv*mv / (9.8f * 2)) / 5 + 1) << endl;

	return 0;
}

C++: #include <iostream>
using namespace std;
#define G 9.8

int main() {
	double v;
	while (cin >> v) {
		double y = v*v/G/2;
		int cnt=1;
		int h = 0;
		while (1) {
			if (y <= h) break;
			cnt++;
			h += 5;
		}

		cout << cnt << endl;
	}
	return 0;
}

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


int main(){
	
	double v,t,y;
	while(cin>>v){
		t=v/9.8;
		y=t*t*4.9;
		cout<<(int)y/5+2<<endl;
	}
	
	return 0;
}

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


int main(){
	float v, t, h;
	int n, a;
	while (true){
		cin >> v;
		if (cin.eof()) { break; }
		t = v / 9.8;
		h = 4.8 * t * t;
		for (n = 0;;n++){
			a = 5 * n - 5;
			if (a > h) { break; }
		}
		cout << n << endl;
	}
	return 0;
}

C++: #include<iostream>
using namespace std;
int main() {
	double v;
	while (cin >> v){
		double y = (v / 9.8)*(v / 9.8) * 4.9;
		y -= 5;
		int n = 0;
		while (true){
			if (5 * n >= y){
				cout << n << endl;
				goto grav;
			}
			else n++;
		}
	grav:;
	}
}

C++: #include<stdio.h>
int main()
{
    int n;
    float v,y;
    while (scanf("%f",&v)!=EOF)
    {
        y=(v/9.8)*(v/9.8)*4.9;
        n=int((y+5)/5)+1;
        printf("%d\n",n);
    }
    return 0;
}

C++: #include<iostream>
using namespace std;
int main()
{
long double v,n;
int N;
while(cin>>v)
{
n=0;
N=0;
n=4.9*(v/9.8)*(v/9.8)/5+1;
N=n*10;	
if(N%10==0)
{
	cout<<N/10<<endl;
}
else if(N%10!=0)
{
	cout<<N/10+1<<endl;
}
}
return 0;
}

C++: #include <iostream>

using namespace std;


int main(void)
{
	double v, t, y, n;

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

		for( n=0; 5*n-5<y; n++ );

		cout << n << endl;
	}
	return 0;
}

C++: //何階から落とす？
#include<cstdio>

using namespace std;

int main(void){
	double in,y,h,t;	//y=必要な高さ,in=最低速度,t=必要な時間
	int ans;	//必要な階

	while(scanf("%lf",&in)==1){
		t=in/9.8;
		y=4.9*(t*t);
		for(ans=1;ans<1000;ans++){
			h=5*ans-5;
			if(y<=h){
				printf("%d\n",ans);
				break;
			}
		}
	}

	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 < 0.0000001) {
            printf("%d\n", (int)ans + 1);
        } else {
            printf("%d\n", (int)ans + 2);
        }

    }

    return 0;
}

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



int main() {
	double a;
	while(cin >> a,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++: //Physical Experiments
#include<bits/stdc++.h>
using namespace std;

int main(){
  double min_v;
  while(cin >> min_v){
    cout << ceil(pow(min_v, 2.0)/(9.8*2.0*5.0)+1) << endl;
  }
  return 0;
}

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

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

C++: #include <iostream>
#include <cmath>
using namespace std;
int main() {
	double v;
	while (cin >> v) {
		double N = (4.9*(v/9.8)*(v/9.8))/5.0+1.0;
		cout << (int)ceil(N) << endl;
	}
	return 0;
}

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

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

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

int main(void){
  const double g = 9.8;
  const double height = 5.0;
  double v, y;
  int N;
  while(cin >> v){
    y = (v * v) / (2 * g);
    N = y / height + 1;
    if(y % height != 0)
      N++;
    
    cout << 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;
    int n = 1;
    while (5 * n - 5 < y) {
      n++;
    }
    cout  << n << endl;
  }
}

C++: #define _USE_MATH_DEFINES
#include <iostream>
#include <queue>
#include <vector>
#include <math.h>
#include <algorithm>
#include <iomanip>
#include <string>
#include <stack>
#include <cctype>
#include <cstdlib>
using namespace std;

#define INF (1 << 20)
#define EPS (1e-10)
#define EQ(a,b) (fabs((a)-(b)) < EPS)

int main(){
	double v;
	while (cin >> v) {
		int n = 0;
		while (n - v * v / 98 - 1.0 < EPS) ++n;
		cout << n << endl;
	}
	return 0;
}

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

int main()
{
  double v, y;

  while (cin >> v){
    int floor = 0;
    y = (v * v) / (2 * 9.8);
    for (; (floor * 5) - 5 < y; floor++);
    printf("%d\n", floor);
  }
}

C++: #include<iostream>
#include<cmath>
#define REP(i,s,n) for(int i=0;i<n;i++)
#define rep(i,n) REP(i,0,n)
using namespace  std;

int main(){
  long double n;cin >>n;
  // cout << n*n/19.6<<endl;
  // cout << int(35.0+1.2)<<endl;
  cout <<int(n*n/19.6/5+2) << endl;
  return 0;
}

C++: #include <iostream>
#include <cmath>
using namespace std;
int main( void )
{
	while ( !cin.eof() )
	{
		double v_min;
		cin >> v_min;
		if ( cin.eof() )
			break;

		double v = 0.0;
		int N = 1;
		do
		{
			double y = 5 * N - 5;
			double t = sqrt( y / 4.9 );

			v = 9.8 * t;

			N++;
		} while( v < v_min );

		cout << N-1 << endl;

	}
	return 0;
}