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()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    double v;
    while(cin>>v) {
        double y=v*v/19.6;
        cout<<(int)(y+4.9)/5+1<<'\n';
    }
    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;
		cout<<t<<endl;
		while(5*n-5<=4.9*t*t){
			n++;
		}
		cout<<n<<endl;
	}
}

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

using namespace std;

int main (void) {
    while (1) {
        double v0, v;
        cin >> v0;
        if (cin.eof()) break;
        for (int n = 0; ; n++) {
            v = 9.8 * sqrt((5 * n - 5) / 4.9);
            if (v >= v0) {
                cout << n << endl;
                break;
            }
        }
    }
    return 0;
}

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

//using namespace--------------------------------------------------------------------------------------------------------------
using namespace std;

//define-----------------------------------------------------------------------------------------------------------------------
#define rep(i, n) for(int i = 0; i < n; i++)
#define FOR(i, s, n) for(int i = s; i < n; i++)
#define per(i, n) for(int i = n; i >= 0; i--)
#define ROF(i, s, n) for(int i = s; i >= n; i--)
#define FORIT(i, A) for (auto i : A)
#define PRINT(x) cout << (x) << endl
#define ALL(a)  (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define FOREACH(i, n) for (__typeof((n).begin()) i = (n).begin(); i != (n).end(); ++i)
#define SZ(a) int((a).size())
#define EACH(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort((c).begin(),(c).end())
#define INF 1 << 25
#define CLR(a) memset((a), 0 ,sizeof(a))
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;
#define sq(n) (n) * (n)

//typedef----------------------------------------------------------------------------------------------------------------------
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef long long LL;
typedef unsigned int uint;
typedef unsigned long long ull;

//const------------------------------------------------------------------------------------------------------------------------
const double EPS = 1e-10;
const double PI = acos( -1.0 );

//global-----------------------------------------------------------------------------------------------------------------------
double a;
double test;

//function---------------------------------------------------------------------------------------------------------------------
int main() {
	while ( scanf( "%lf", &a ) != EOF ) {
		for ( int i = 2;; i++ ) {
			test = ( i * 5 - 5 );
			test /= 4.9;
			test = sqrt( test );
			if ( test * 9.8 >= a ) {
				printf( "%d\n", i );
				break;
			}
		}
	}
	return 0;
}

C++: #???script?????????????????????????????£???

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

int main()
{
	double velocity = 0;
	while (std::cin >> velocity) {
		double time = velocity / 9.8;
		double y = 4.9 * time * time;
		int floor = static_cast<int>(y / 5.0) + 2;
		std::cout << floor << std::endl;
	}

	return 0;
}

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

double speed(int i){
	double height = i * 5 - 5;
	return 2 * 9.8 * height;
}
int main(){
	double vl;
	while(cin >> vl){
		int i = 0;
		while(speed(i) < vl * vl) i++;
		cout << i << endl;
	}
	return 0;
}

C++: // 2014/06/09 Tazoe

#include <iostream>
#include <cmath>
using namespace std;

int main()
{
	while(true){
		double v;
		cin >> v;

		if(cin.eof())
			break;

		int N = ceil(v*v/98.0+1.0);

		cout << N << endl;
	}

	return 0;
}

C++: #include <iostream>
using namespace std;
 
int main() {
  double v;
  while(cin >> v) {
    double N = (v*v)/98+1;
    if(N != (int)N) N++;
    cout << (int)N << endl;
  }
  return 0;
}

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

//#define int long long
#define DBG 1
#define dump(o) if(DBG){cerr<<#o<<" "<<o<<endl;}
#define dumpc(o) if(DBG){cerr<<#o; for(auto &e:(o))cerr<<" "<<e;cerr<<endl;}
#define rep(i,a,b) for(int i=(a);i<(b);i++)
#define rrep(i,a,b) for(int i=(b)-1;i>=(a);i--)
#define each(it,c) for(auto it=(c).begin();it!=(c).end();it++)
#define all(c) c.begin(),c.end()
const int INF = sizeof(int) == sizeof(long long) ? 0x3f3f3f3f3f3f3f3fLL : 0x3f3f3f3f;
const int MOD = (int)(1e9 + 7);

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

C++: #include<iostream>

int main(){

	double min_v;
	while (std::cin >> min_v){

		double t = min_v / 9.8;
		double sum = 4.9*t*t;

		int y = (sum + 5) / 5;

		std::cout << (5 * y - 5 > sum ? y : y + 1) << std::endl;
	}

	return 0;
}

C++: 
#define _USE_MATH_DEFINES
#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cmath>
#include <string>
#include <cstring>
#include <vector>
#include <map>
#include <utility>
#include <complex>
#include <stack>
#include <climits>

using namespace std;

double sq(double x){return x*x;}

int a[5001];

int main(){
	double d;
	while(cin>>d){
		d = sq(d / 9.8) * 4.9 + 5;
		int n = (int)(d / 5);
		if((double)n * 5 != d)
			n++;
		cout << n << endl;
	}

	return 0;
}

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

using namespace std;

#define FOR(i, j, k) for(int i = j; i < k; ++i)
#define rep(i, j) FOR(i, 0, j)
#define repr(i, j) for(int i = j; i >= 0; --i)
#define INF (1 << 30)
#define MOD 1e9 + 7

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

int num[5000];

int main() {
	double v;
	while(scanf("%lf", &v) != EOF) {
		rep(i, 1000) {
			double y = 5 * i - 5;
			double t = sqrt(y / 4.9);
			double a = 9.8 * t;
			if(a > v) {
				printf("%d\n", i);
				break;
			}
		}
	}
	return 0;
}

C++: #include<iostream>
#include<cmath>
#include<cstdio>
using namespace std;
int main()
{
	double v;
	double t , y , n;
	while ( cin >> v )
	{
		t = v / 9.8;
		y = 4.9*t*t;
		n = ( y + 5 ) / 5;
		printf("%.0f\n" , n);
	}
}

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

using namespace std;

int main(void){
	double sp;
	while(cin >> sp){
		double t=(double)sp/9.8;
		t=pow(t,2);
		t*=4.9;
		int f=0;
		while(1){
			if((f-1)*5>t){
				printf("%d\n",f);
				break;
			}
			f++;
		}
	}
    return 0;
}

C++: #include <iostream>
#include <cmath>
#include <cstdlib>
#include <cstring>
#include <vector>

using namespace std;

int main(){
	double v;

	while(cin >> v){
		double m = (v*v)/(4*4.9);
		for(int i = 0; i < 10000; i++){
			if(m <= i*5-5){
				cout << i << endl;
				break;
			}
		}
	}

	return 0;
}

C++: #include <cstdio>
#include <algorithm>
#include <functional>
#include <stack>
#include <cmath>
using namespace std;

#define REP(i, n) for(int i = 0;i < n;i++)
#define REPR(i, n) for(int i = n;i >= 0;i--)
#define FOR(i, m, n) for(int i = m;i < n;i++)
#define llong long long

int main() {
  double v;
  while(scanf("%lf",&v) != EOF) {
    double t = v/9.8;
    double d = 4.9*t*t;
    double dover5 = d/5;
    int N = (dover5-(int)dover5 == 0)? (int)dover5+1: (int)dover5+2;
    printf("%d\n", N);
  }
  return 0;
}

C++: #include<stdio.h>
int main(){
	double v=0.0,t=0.0,y=0.0;
	
	while(scanf("%lf",&v)!=EOF){
	t=v/9.8;
	y=4.9*t*t;
	printf("%.0f\n",(y/5+1));
	}
return 0;
}