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 <sstream>
#include <string>
#include <vector>
#include <deque>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <bitset>
#include <algorithm>
#include <numeric>
#include <complex>
#include <functional>
#include <utility>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <climits>
#include <cctype>

using namespace std;

#define dump(n) cout<<"# "<<#n<<"="<<(n)<<endl
#define debug(n) cout<<__FILE__<<","<<__LINE__<<": #"<<#n<<"="<<(n)<<endl
#define repi(i,a,b) for(int i=int(a);i<int(b);i++)
#define rep(i,n) repi(i,0,n)
#define iter(c) __typeof((c).begin())
#define tr(c,i) for(iter(c) i=(c).begin();i!=(c).end();i++)
#define allof(c) (c).begin(),(c).end()
#define mp make_pair

typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<string> vs;
typedef pair<int,int> pii;

int main()
{
	for(double v;cin>>v;){
		int n=ceil(v*v/98+1)+1e-10;
		cout<<n<<endl;
	}
	
	return 0;
}

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

#define PI 4*atan(1);

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

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

int main() {
  int i;
  double v,vmin;
  while(cin >> vmin) {
    i=1;
    while(1) {
      v = 9.8 * sqrt((5*i-5)/4.9);
        if(v >= vmin) break;
        i++;
    }
    cout << i << endl;
  }
}

C++: #include <stdio.h>
#include <stdlib.h>
#include <iostream>
using namespace std;
int main(){
    double x,y,i,s,n,s1;
    while( scanf("%lf", &n)!=EOF){
           
           y=(n*n)/19.6;
           if(n>1)
           cout <<int ((y+5)/5)+1<<endl;                         
           else
           cout <<"1";
           
    }
    return 0;
        
}

C++: #include<stdio.h>
#define EPS 1e-9
double v;

int main(){
	double h;
	int ans;
	while( scanf("%lf",&v) != EOF )
	{
		h = (v*v)/19.6;
		ans = h/5.0;
		h -= ans*5.0;
		if( h > EPS )
			ans++;
		ans++;
		
		printf("%d\n",ans);
	}
	return 0;
}

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

int main()
{
  double v0;
  while (scanf("%lf ", &v0) == 1) {
    cout << (int)((v0 * v0)/ (5.0 * 4.0 * 4.9) + 0.5) + 1 << endl;
  }
}

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

int keta(int x){
	int i=0;
	while (x/pow(10,i)>=1){
		i++;
	}
	if (x==0){
		return 1;
	}
	else
	return i;
	}


int main(){
double min;
while (cin>>min){
	double y;
	int N;
	y=4.9*(min/9.8)*(min/9.8);
	N=ceil((y+5)/5);
	cout<<N<<endl;

}

}

C++: #include <iostream>
#include <math.h>
using namespace std;
int main()
{
	double v;
	double c = 4.9 / 9.8 / 9.8 / 5.0;
	while (cin >> v){
		int floor = int(ceil(c * v * v)) + 1;
		cout << floor << "\n";
	}
	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=2.0*9.8*(5*h-5);

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

		if( v*v<=2.0*9.8*(5*l-5) ) cout<<l<<endl;
		else cout<<r<<endl;

	}

	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 < 0.0000000001) {
            printf("%d\n", (int)ans + 1);
        } else {
            printf("%d\n", (int)ans + 2);
        }

    }

    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 < 0.00000000001) {
            printf("%d\n", (int)ans + 1);
        } else {
            printf("%d\n", (int)ans + 2);
        }

    }

    return 0;
}

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

const int INF = 1e+9 * 2;
double eps = 1e-10;

int main() {
	long double v;
	while(cin >> v){
		long double n = (4.9 * pow(v / 9.8, 2.0) + 5.0) / 5.0;
		if(n - (int)n < eps)
			cout << (int)n << endl;
		else
			cout << (int)n + 1 << endl;
	}
	return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <stack>
#include <queue>
#include <cstring>
#include <climits>
#include <cmath>
#include <cfloat>

using namespace std;

double v, y, out, t;

int main()
{
	
	while( cin >> v, !cin.eof())
	{
		t = v/9.8;
		y = t*t*4.9;
		
		for( int i = 1; i < INT_MAX; i++)
		{
			int f = 0;
			double flr = (double)(i-1)*5.0;
			
			if( flr >= y )
			{
				cout << i << endl;
				f = 1;
				break;
			}
			
			if(f)
				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=(((y+5)/5)*10+9)/10;
		
		/*for(int i=0;0<y;i++){
			y-=5;
			c++;
		}*/
		cout<<n<<endl;
	}
}

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

using namespace std;

int main() {
	double crackSpeed;
	
	crackSpeed = -1;
	cin >> crackSpeed;
	
	while (crackSpeed >= 0) {
		
		double crackTime = crackSpeed / 9.8;
		double crackDist = 4.9 * crackTime * crackTime;
		
		int numFloor = 1;
		
		while ((double)(5 * numFloor - 5) < crackDist) numFloor++;
		
		cout << numFloor << endl;
		
		crackSpeed = -1;
		cin >> crackSpeed;
	}
	
	return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <cstring>
#include <sstream>
#include <algorithm>
#include <math.h>
#include <map>
#include <functional>
#include <iomanip>
#include <vector>
#include <queue>
#include <stack>
#include <set>
#include <typeinfo>
#define PI 3.14159265359
#define INF 99999999
#define rep(i, n) for(int i=0; i<n; i++)
#define REP(n) rep(i, n)
#define EPS 1e-10
#define pb push_back
#define mp make_pair
typedef long long ll;
using namespace std;
typedef pair<int, int> P;

int v;

int main()
{
	while (cin >> v)
	{
		int ans = 1.0 * v * v / (5 * 19.6) + 1;
		cout << ans + 1 << 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<100;i++){
		if((i*5-5)>y){
			cout<<i<<endl;
		break;
		}
	}	
	}
}

C++: #define _USE_MATH_DEFINES
#include<iostream>
#include<iomanip>
#include<algorithm>
#include<cctype>
#include<cmath>
#include<cstdio>
#include<deque>
#include<list>
#include<set>
#include<stack>
#include<string>
#include<sstream>
#include<map>
#include<queue>
#include<vector>
using namespace std;

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

C++: #include <iostream>
#include <iomanip>
#include <math.h>
#include <utility>
#include <vector>
#include <cstdlib>
#include <algorithm>
#include <climits>
using namespace std;

int main(){
	double x;
	while(cin>>x){
		double h = 4.9*x*x/9.8/9.8;
		int y=0;
		while(5*y-5<h) y++;
		cout << y << endl;
	}
	return 0;
}