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 <cstdio>
#include <cstdlib>
#include <cstring>
#include <climits>
#include <cmath>
#include <ctime>
#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <deque>
using namespace std;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<double> vd;
typedef vector<vd> vvd;
typedef pair<int,int> pii;
typedef map<int,int> mii;
#define PI acos(-1.)
#define SQR(x) ((x)*(x))
#define INF (INT_MAX/100)
#define mid(x,y) (x+y)/2
#define ll long long
#define sz(v) ((int)(v).size())
#define rep(i, n) for (int i=0; i<(n); ++i)
#define repf(i, a, b) for (int i=(a); i<=(b); ++i)
#define repd(i, a, b) for (int i=(a); i>=(b); --i)
#define fill(a, b) memset(a, b, sizeof(a))
#define clr(q) while (!q.empty()) q.pop();
#define pb push_back
#define pf push_front
#define itr iterator
#define eps 1e-9

int sgn(double d){
    return d<-eps?-1:d>eps;
}

int main(){
    double v;
    while (~scanf("%lf", &v)){
        cout<<(unsigned ll)ceil(v*v/98+1)<<endl;
    }
    return 0;
}

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

int main()
{
	double get ;
	double high ;

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

		int i ;
		for( i = 0 ; ; i ++ )
		{
			double tmp = high ;
			tmp -= i*5 ;

			if( tmp < 5 )
			{
				break ;
			}
		}

		cout << i+2 << endl ;
	}

	return 0 ;
}

C++: main(){float v;for(;~scanf("%f",&v);printf("%.f\n",v*v/88+1));}

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

using namespace std;

int main(void){
    double v;
    
    while (cin>>v)
    {
        double n,k;
        n = (4.9*(v/9.8)*(v/9.8)+5)/5;
        k=n-(int)n;
        if(0==k);
        else {n++;}
        cout<<(int)n<<endl;
    }
    return 0;
}

C++: #include <stdio.h>
 
int main(void){
	float v,t,y,n1;
	int n;
	while(scanf("%f",&v)!=EOF){
		fflush(stdin);
    	t=v/9.8;
    	y=4.9*t*t;
    	n=0;
    	n1=(5+y)/5;
    	while(n<n1){
    		n=n+1;
    	}
		printf("%d\n",n);
    }
	return 0;
}


//debug for alfa

C++: #include <iostream>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <functional>
#include <string>
#include <algorithm>
#include <climits>
#include <utility>

#define PRINT(STR) cout << STR << endl;
#define REP(i, n) for (int (i) = 0; (i) < (int)(n); (i)++)
#define REG(i, a, b) for (int (i) = ((int)(a)); (i) < ((int)(b)); i++)
#define ALL(V) (V).begin(), (V).end()

typedef long long ll;

using namespace std;

int nextInt() { int n = -1; cin >> n; return n; }
double nextDouble() { double d = -1; cin >> d; return d; }
ll nextll() { ll n = -1; cin >> n; return n; }
string nextString() { string str; cin >> str; return str; }

int INF = 1LL << 25;
double EPS = 1e-9;

// BEGIN //////////////////////////////////////////////////////////////

int main() {
	double v;
	while (scanf("%lf", &v) != EOF) {
		int N = ceil((4.9 * (v / 9.8) * (v / 9.8) + 5) / 5);
		PRINT(N);
	}
	return 0;
}

// END   //////////////////////////////////////////////////////////////

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

#define rep(x,to) for(int x=0;x<to;x++)
#define rep2(x,from,to) for(x=from;x<to;x++)

using namespace std;


int main(void){

double v,wn;
int n;

	while(cin >> v ){
		double h = 4.9 * (v / 9.8) * (v / 9.8);
		wn = (( h + 5 ) / 5);
		n = (int)wn;
		n = n + (wn==n? 0: 1);
		cout << n << endl;
	}
	
	return 0;
}

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

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

int main void{
while(1){
double a;
cin >> a;
double b = a / (9.8);
double c = b*b*(4.9);
double i = 1;
while(1){
if((5*i-5)>=i) break;
i++;
}
cout << i << endl;
}
return 0;
}

C++: #include <iostream>

int main()
{
	double v;
	while( std::cin >> v )
	{
		double t = v / 9.8;
		double y = 4.9 * t * t;
		int f = static_cast<int>( (y+5.0)/5.0 ) + 1;

		std::cout << f << '\n';
	}
}

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

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

constexpr double GRAVITY = 9.8;

double floor_velo(int floor);

int main(void)
{
    double crash_velo;
    while (std::cin >> crash_velo) {
        int floor = 1;
        while (crash_velo > floor_velo(floor)) {
            floor++;
        }

        std::cout << floor << std::endl;
    }

    return 0;
}

double floor_velo(int floor)
{
    int height = 5 * (floor - 1);
    return (GRAVITY / sqrt(GRAVITY / 2)) * sqrt(height);
}

C++: #include<iostream>
#include<math.h>
using namespace std;
int main() {
	int N,high;
	double v, y;
	while (cin >> v) {
		N = 1;
		high = 0;
		y = pow(v,2) / 19.6;
		while (high < y) {
			N += 1;
			high += 5;
		}
		cout << N << endl;
	}
	return 0;
}

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

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

C++: #include <iostream>
using namespace std;
int main()
{
    double v;
    while(cin >> v,v)
    {
        double t = 0,y = 0;
        t = v/9.8;
        y = 4.9*t*t;

        double f = 0;
        y = y-5;
        f = y/5;
        cout << f+1 << endl;
    }
}

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

using namespace std;

int main()
{
    double v;

    while (scanf("%lf", &v) != EOF) {
        double ans = v*v + 98.0;
        for (int i = 0; i < 500; i++) {
            if (ans <= 98 * i) {
                cout << i << endl;
                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 = (int)ceil((y + 5) / 5);

		cout << N << endl;
	}

	return 0;
}

C++: #include <stdio.h>
#include <float.h>

int main(void)
{
  int i=0;
  long double v,floar;

  while(scanf("%Lf", &v) != EOF && i<50){
    floar = (v*v/98)+1;  
    if(floar - (int)floar > LDBL_EPSILON){
      floar++;
    }
    printf("%d\n", (int)floar);
    i++;  
  }
  return 0;
}

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

using namespace std;

double getT(double v){return v/9.8;}
double getY(double t){return 4.9*t*t;}

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

	while(cin>>v,v!=EOF){
		int N=0;
		t=getT(v);

		y=getY(t);

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

		cout<<N<<endl;
	}
	return 0;
}

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

int main(){
    double v;
    int N;
    while(scanf("%lf",&v)!=EOF){
        N = (int)ceil((v*v)/98.0 + 1);
        if(N<1)N=1;
        printf("%d\n",N);
    }
}

C++: #include <iostream>

using namespace std;

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

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

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

int main(){
    double v;
    double y;
    int n = 2;

    while(cin >> v){
        y = (v * v) / (2.0 * 9.8);
        while(y > 5 * n - 5){
            n++;
        }
        cout << n << endl;
    }

    return 0;
}