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<stdio.h>

int main(void)
{
	double v,t,y;
	int n=1,h=0;
	while(scanf("%lf",&v)!=EOF)
	{
		t = v / 9.8;
		y = 4.9 * t*t;
		while(h<y)
		{
			n++;
			h=5*n-5;
		}
		printf("%d\n",n);
		n=1;
		h=0;
	}
	return 0;
}

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

#define rep(i, n) REP(i, 0, n)
#define ALL(v) v.begin(), v.end()
#define MSG(a) cout << #a << " " << a << endl;
#define REP(i, x, n) for (int i = x; i < n; i++)
#define OP(m) cout << m << endl;
typedef long long ll;
typedef unsigned long long ull;

int main()
{
    double v;
    while (cin >> v)
    {
        double t = v / 9.8;
        double y = 4.9 * t * t;
        OP(ceil((y + 5) / 5))
    }
    return 0;
}

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

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

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

  return 0;
}

C++: #include <iostream>
using namespace std;
int main(){
  double v;
  while(cin>>v){
    double y,t;
    t = v/9.8;
    y = 4.9*t*t;
    cout<<(int)(y/5+2)<<endl;
  }
}

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

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

	while (cin >> v)
	{
		if (cin.eof()) break;

		t = v / 9.8;
		N = (int)((4.9 * t * t + 5) / 5 + 0.9);
		cout << N << endl;
	}
	return 0;
}

C++: #include<iostream>
#include<cmath>
using namespace std;
int main()
{
	double v,y;
	while(cin>>v){
	y=4.9*v/9.8*v/9.8;
	for(int i=1;i!=1000000;i++){
		if((i*5-5)>y){
			cout<<i<<endl;
		break;
		}
	}	
	}
}

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

int main(){
	double v, t, y;
	int n, h[100000];
	
	for(int i=0 ; i<100000 ; i++){
		h[i] = i*5-5;
	}

	while(cin >> v){
		t = v / 9.8;
		y = t*t*4.9;
		n = (int)( (y+5.0)/5.0 );
		for(int i=0 ; i<100000 ; i++){
			if(h[i]>=y){
				n = i;
				break;
			}
		}
		cout << n << endl;
	}
}

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

#define REP(i, a, b) for (int i = (int)(a); i < (int)(b); ++i)
#define rep(i, n) REP (i, 0, n)
#define mset(a, n) memset(a, n, sizeof(a))

using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> pii;
typedef vector<pair<int, int> > vpii;

int main() {
	double n;
	while (cin >> n) {
		double t = n / 9.8;
		double y = 4.9 * t * t;
		// 繰り上げ関数ceil
		int ans = ceil((y + 5) / 5);
		cout << ans << endl;
	}
}

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

int main(){
    double v;
    double y;
    int n = 1;

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

    return 0;
}

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

int main() {
  double input;

  while(cin >> input){
    double n = (input * input / 19.6 + 5) / -5;
    
    cout << -n << endl;
    
  }

  return 0;

}

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

using namespace std;

int main() {
	double a;
	double time;
	int kai;
	while (cin >> a) {
		time = a / 9.8;
		kai = (4.9 * time * time + 5) / 5 + 1;
		cout << kai << endl;
	}

	return 0;
}

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

int main() {
  double input;

  while(cin >> input){
    double n = (input * input / 19.6 + 5 - 0.0000001) / 5;
    
    cout << (int)(n + 1) << 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);
		cout << (y + 5) / 5 + 1 << endl;
	}
	
	return 0;
}

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

int main()
{
	double velocity;
	while (std::cin >> velocity) {
		double const gravity = 9.8;
		double const y = velocity * velocity / (2 * gravity);
		std::cout << std::ceil((y + 5) / 5) << std::endl;
	}
	return 0;
}

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

int rheight(double h){
	return (int)ceil(h / 5 + 1);
}

int main(void){
	double v = 0.0;
	double t, y;
	while(scanf("%lf", &v) != EOF){
		y = v * v / 9.8 / 2;
		printf("%d\n", rheight(y));
	}
	return 0;
}

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

int main()
{
    double v;
    while(cin>>v)
    {
        double t = v/9.8;
        double dis = 4.9*t*t;
        int ans = dis/5;
        if(dis-ans*5>0.000000001)
        {
            ans++;
        }
        ans++;
        cout<<ans<<endl;
    }
    return 0;
}

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

int main(){
    double v;
    double y;
    int n = 1;

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

    return 0;
}

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

using namespace std;

int main() {
	float v;
	while (scanf("%f", &v) != EOF) {
		double n = (v * v / 19.6 + 5) / 5.0;
		if ((int)n != n) ++n;
		printf ("%d\n", (int)n);
	}
	return 0;
}

C++: #include <stdio.h>

int main(void) {

  double v,y;
  int n;

  
  while(scanf("%lf",&v)!=EOF) {

    printf("%d\n",(int)(v*v/(19.6*5.0))+2);

  }

  return 0;
}

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

int main()
{
	double limit;
	int floor;
	while (scanf("%lf", &limit) != EOF)
	{
		for (floor = 0;; floor++)
		{
			double speed = sqrt(19.6 * 5 * (floor - 1));
			if (speed >= limit)
			{
				printf("%d\n", floor);
				break;
			}
		}
	}
	return 0;
}

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

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

C++: #include<stdio.h>
#include<math.h>
int main()
{
int N;
double v,y,x,t;
while(scanf("%lf",&v)!=EOF)
{

t=v/9.8;
y=4.9*t*t;
x=(y+5)/5;


N=(int)x;
N = (x - (double)N) ? N+1 : N;

printf("%d\n",N);
}
return 0;
}

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

using namespace std;

int main(void){
	int n;
	double mv;
	while(scanf("%lf",&mv) != EOF){
		for(n = 1;sqrt(19.6 * (5 * n - 5)) < mv;n++);
		printf("%d\n",n);
	}
	return 0;
}

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

}

C++: #include <stdio.h>

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

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

  return 0;
}

C++: #include <iostream>
#include <string>
#include <vector>
#include <cmath>
#include <algorithm>
#include <cstdlib>
#include <ctime>
#include <cstdio>
#include <functional>
#include <set>
#include <sstream>
#include <map>

using namespace std;

const double eps=1e-10;

int main()
{
	double v;
	while(cin>>v){
		unsigned long long l=1,r=1e16,h;

		for(int i=0;i<1000;i++){

//			cout<<l<<" "<<r<<endl;

			h=(l+r)/2;
			double vv=(5*h-5)/4.9*9.8*9.8;

			if(v*v>vv) l=h;
			else if(v*v<vv) r=h;
		}

		if( v*v-(5*l-5)/4.9*9.8*9.8<=eps ) cout<<l<<endl;
		else cout<<r<<endl;

	}

	return 0;
}

C++: #include<iostream>
#include<cstdlib>
#include<cmath>
using namespace std;
#define G 9.8
int main(){
	double v;
	while(cin>>v){
		v = pow(v,2);
		v = v/(2*G) + 5;
		v /= 5;
		cout<<((int)v+1)<<endl;	
	}
	return 0;
}

C++: #include<iostream>
using namespace std;
int main(){
	double v0,t;
	int N=1;
	while(cin>>v0){
		t=0;
		t=v0/9.8;
		while(5*N-5>=4.9*t*t){
			N++;
		}
		cout<<N<<endl;
	}
}

C++: #include <iostream>

using namespace std;

void solve()
{
	double velocity;
	while(cin >> velocity)
	{
		double time = velocity / 9.8;
		double height = 4.9 * time * time;
		int level = 0;
		cout << (unsigned long long int)((height + 5) / 5 + 1.0) << endl;
	}
}

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