Go: package main

import (
        "fmt"
        "math"
)

func main() {
        var v, t, h float64
        for {
                _, err := fmt.Scanf("%f", &v)
                if err != nil {
                        break
                }
                t = v / 9.8
                h = 4.9 * t * t
                n := math.Floor(h/5+1.0) + 1.0
                fmt.Printf("%d\n", int(n))
        }
}

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

int main(void) {
    double speed;
    while(cin >> speed) {
        double y = (speed / 2) * (speed / 9.8);
        double n = (y + 5) / 5.0;
        printf("%.0f\n", n);
    }
    return(0);
}

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

int main() {
  double v;
  while(cin >> v) {
    double N = v*v/98.0+1;
    if(N != (int)N) ++N;
    cout << (int)N << endl;
    //cout << (int)ceil(v*v/98.0+1) << endl;
  }
  return 0;
}

C++:  
 #include<iostream>
 #include<stdio.h>
 #include<string>
 #include<math.h>
 #include<iomanip>
 #include<algorithm>
 #include<string.h>
 #include<cctype>
 #include<map>
 #include<set>
 #include<vector>
 #include<sstream>
 #include<stack>
 
 using namespace std;
 
 double abs(double x)
 {
   if(x<0) return -x;
   else return x;       
 }
  
 int main()
 {
   int v;
   while(cin>>v)
   {
     double t=v/9.8;
     double h=4.9*t*t;
     int N=(int)((h+5)/5)+1;
     cout<<N<<endl;
   }
   //while(1);      
   return 0;    
 }

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

int main(){
	int n;
	while(cin >> n){
		n = n*n/19.6;
		n = (n+5)/5;
		cout << n <<"\n";
	}
	return 0;
}

C++: #include<stdio.h>
#include<iostream>
#include<list>
#include<map>
#include<vector>
#include<algorithm>
#include<string.h>
#define range(i,a,b) for(int i = (a); i < (b); i++)
#define rep(i,b) range(i,0,b)
#define debug(x) cout << x << endl;
using namespace std;

int main(){
    double input, time, height;

    while(cin >> input){
        time = input / 9.8;
        height = 4.9 * time * time;
        rep(i, 10000){
            if(height < 5 * i - 5){
                cout << i << endl;
                break;
            }
        }
    }
}

C++: 
#include <iostream>
#include <cstdlib>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <stack>
#include <cctype>
#include <complex>
#include <vector>
#include <algorithm>
#include <cassert>

using namespace std;


bool solve(){
	double in;
	while(cin>>in){
		int y = 4.9 * (in/9.8) * (in/9.8);
		int ans = 0;
		for(int i=1;i<10000;i++){
			int h = 5 * (i - 1);
			if(h > y){
				ans = i;
				break;
			}
		}
		cout<< ans<< endl;
	}
	return true;
}

int main(){
	cout.setf(ios::fixed);
	cout.precision(10);
	solve();

	return 0;
}

C++: #include <iostream>
#include <stdio.h>
using namespace std;
int main(){
  int nr;
  double v,n;
  while(scanf("%lf",&v)!=EOF){
    n=(v*v+98)/98;
    nr=n*10;
    if(nr%10!=0) cout << nr/10+1 << endl;
    else cout << nr/10 << endl;
  }
  return 0;
}

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



int main() {
	double a;
	while(cin >> 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++: #include <iostream>
using namespace std;
int main(void){
    double v;
    double t; //球が割れるのに必要な最低速度になるのは落下し始めてから何秒後か
    double y; //t秒後に物体が落下した距離
    int N; //球が割れる建物の階の最小値

    while(cin >> v){
        t = v / 9.8;
        y = 4.9 * t * t;
        N = (y + 5) / 5; 

        cout << N + 1 << endl;
    }
}

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

typedef pair<double,double>vec;

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

C++: #include<stdio.h>
#include<math.h>
#include<limits.h>
int main()
{
	double V,y,v,t;
	while(scanf("%lf",&V)>0)
	{
		int l=0,r=INT_MAX,m;
		while(l<r)
		{
			m=(l+r)/2;
			y=5.*m-5;
			t=sqrt(y/4.9);
			v=9.8*t;
			if(V<=v)r=m;
			else l=m+1;
		}
		printf("%d\n",l);
	}
	return 0;
}

C++: // clang-format off
#include <bits/stdc++.h>
#define int long long
#define main signed main()
// #define main int main()
#define loop(i, a, n) for (int i = (a); i < (n); i++)
#define rep(i, n) loop(i, 0, n)
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()
#define prec(n) fixed << setprecision(n)
#define stlice(from, to) substr(from, (to) - (from) + 1)
#define pb push_back
#define mp make_pair
#define mt make_tuple
#define fi first
#define se second
using namespace std;
using pii = pair<int, int>;
using vi = vector<int>;
using vd = vector<double>;
using vc = vector<char>;
using vb = vector<bool>;
using vs = vector<string>;
using vpii = vector<pii>;
using vvi = vector<vi>;
using vvb = vector<vb>;
using vvpii = vector<vpii>;
template<typename A> using fn = function<A>;
constexpr int INF = sizeof(int) == sizeof(long long) ? 1000000000000000000LL : 1000000000;
constexpr int MOD = 1000000007;
constexpr double PI = acos(-1);
template<typename A, typename B> bool cmin(A &a, const B &b) { return a > b ? (a = b, true) : false; }
template<typename A, typename B> bool cmax(A &a, const B &b) { return a < b ? (a = b, true) : false; }
constexpr bool odd(const int &n) { return n & 1; }
constexpr bool even(const int &n) { return !odd(n); }
template<typename V> constexpr typename V::value_type sum(const V &v) { return accumulate(all(v), 0); }
void solve();
main { solve(); return 0; }
// clang-format on

void solve() {
	double v;
	while(cin >> v) {
		double t = v / 9.8;
		double y = 4.9 * t * t;
		cout << ((int)ceil(y)+10) / 5 << endl;
	}
}

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++: #include <cstdio>

using namespace std;

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

C++: #include<bits/stdc++.h>
using namespace std;
static const double g = 9.8;

double v, t, h;

int main(){
	while(cin >> v){
		t = v / g;
		h = 0.5 * g * t * t;
		//cout << t << " " << h << endl;
		int N = 0;
		while(1){
			if(5 * (N - 1) - 5 <= h && 5 * N - 5 > h) break;
			N++;
		}
		cout << N << endl;
	}
	return 0;
}

C++: #include <stdio.h>
int main(){
	double v,n;
	while(scanf("%lf",&v)!=EOF){
		n = (v*v)/98+1;
		if(n>(double)((int)n)) printf("%d\n",(int)n+1);
		else printf("%d\n",(int)n);
	}
	return 0;
}

C++: #include <stdio.h>
 
int main(void){
	double v,t,y,n1;
	int n;
	while(scanf(" %lf",&v)!=EOF){
    	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