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<iostream>
#include<string>
#include<algorithm>
#include<map>
#include<set>
#include<utility>
#include<vector>
#include<cmath>
#include<cstring>
#include<cstdio>
#define loop(i,a,b) for(int i=a;i<b;i++) 
#define rep(i,a) loop(i,0,a)
#define rp(a) while(a--)
#define pb push_back
#define mp make_pair
#define all(in) in.begin(),in.end()
const double PI=acos(-1);
const double EPS=1e-10;
using namespace std;
typedef long long ll;
typedef vector<int> vi;
int main(){
	double n;
	while(cin>>n){
		double t=n/9.8;
		double y=t*t*4.9+5;
		if((int)y%5)y+=5;
		cout<<(int)(y/5)<<endl;
	}
}

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

using namespace std;

const double eps = 1e-10;

int main() {
	double v;
	while (scanf("%lf", &v) != EOF) {
		double n = (v * v / 19.6 + 5) / 5.0;
		if (!(fabs(n - (int)n) < eps)) n += 1;
		printf ("%d\n", (int)n);
	}
	return 0;
}

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

using namespace std;

int main()
{
	double min_v;
	
	while (cin >> min_v) {
		double crack_height = (min_v * min_v) / 19.6;
		int N = ceil( (crack_height)/5.0 + 1);
		cout << N << endl;
	}
		
	return 0;
}

C++: /***** ?????¬???????????¬?????? *****/

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

#define rep(i,a,n) for(int i=a; i<n; i++)
#define repr(i,a,n) for(int i=a; i>=n; i--)
#define pb(a) push_back(a)
#define fr first
#define sc second
#define INF 999999999

#define X real()
#define Y imag()
#define EPS (1e-10)
#define EQ(a,b) (abs((a) - (b)) < EPS)
#define EQV(a,b) ( EQ((a).X, (b).X) && EQ((a).Y, (b).Y) )
#define LE(n, m) ((n) < (m) + EPS)
#define GE(n, m) ((n) + EPS > (m))

typedef vector<int> VI;
typedef vector<VI> MAT;
typedef pair<int, int> pii;
typedef long long int ll;

typedef complex<double> P;
typedef pair<P, P> L;
typedef pair<P, double> C;

int const MOD = 1000000007;

int main() {
    double n;
    while(cin >> n) {
        double t = n / 9.8;
        double y = 4.9 * t * t;
        int ret_d = ceil(y / 5.0);
        cout << ret_d + 1 << endl;
    }
    return 0;
}

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

int main()
{
  double v;

  while (~scanf("%lf", &v)){
    int i = 1;
    while (1){
      if ((v / 9.8) * (v / 9.8) * 4.9 <= 5 * i - 5){
        printf("%d\n", i);
        break;
      }
      i++;
    }
  }

  return (0);
}

C++: #include <cstdio>
#include <cstring>
#include <algorithm>
#include <string>
#include <cmath>
#include <stack>
#include <vector>
#include <map>
#include <iostream>


using namespace std;

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

C++: #include <iostream>
#include <algorithm>
#include <vector>
#include <cstdio>
#include <string>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <cmath>
#include <functional>
#include <numeric>
#define fi first
#define se second
using namespace std;
bool value(int y,int x,int R,int C){return 0<=y&&y<R&&0<=x&&x<C;}
typedef pair<int,int> pii;
typedef long long ll;
typedef vector<int> vi;
typedef vector<long long > vll;
typedef vector< vi > vvi;
double pie=acos(-1);
int INF=10000009;
int dx[4] = { 0,-1,0,1 };
int dy[4] = { -1,0,1,0 };
int main() {
	double x;
	double n=1.0;
	int N;
	while(true){
		if (cin.eof())break;
		cin>>x;
		while(9.8*pow((5.0*n-5.0)/4.9,0.5)<x){
			n+=1.0;
		}
		N=n;
		cout<<N<<endl;
		n=1.0;
	}
}

C++: #include <stdio.h>

int main(){
	float a;
	float N;
	
	while(scanf("%f",&a) != EOF){
		N = 1+a*a/98;
		if(N - (int)N > 0){
			N = (int)N+1;
		}
		printf("%d\n",(int)N);
	}
	
	return 0;
}

C++: #include <iostream>

int main(void)
{
	double v;
	while(std::cin >> v)
	{
		double t = v/9.8;
		double y = 4.9*t*t;
		std::cout << (int)(y/5.0+1)+1 << std::endl;
	}
	return 0;
}

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

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

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

int main(){
	double d,y;
	int res;
	while(cin>>d){
		y=d*d/19.6;
		res=ceil(y);
		res=max((res-1)/5+2,1);
		cout<<res<<endl;
	}
	return 0;
}

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

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

C++: #include<iostream>

using namespace std;

int main(void){

	double y,v,t;
	int step;
	while(cin>>v){
		t=y=0;
		step=0;
		t=v/(9.8);
		y=4.9*t*t;
		step=(int)((y+5)/5)+1;

		printf("%d\n",step);
	}
}

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

int main(void){

	double vel;
	int N;

	while(scanf("%lf",&vel)!=EOF){
		N=1;
		while(9.8*sqrt((5*N-5)/4.9)<vel){
			N++;
		}
		printf("%d\n",N);
	}

	return 0;
}

C++: //#define _USE_MATH_DEFINES
#include <cmath>
#include <iostream>
//#include <stdio.h>
//#include <stdlib.h>
//#include <iomanip>
#include <vector>
//#include <string>
//#include <algorithm>
//#include <functional>
//#include <time.h>
//#include <sstream>
//#include <queue>

using namespace std;


int main(){

	const int H = 5;
	double v, t, y;
	int ans;

	while (cin >> v){
		t = v / 9.8;
		y = 4.9 * t * t;
		ans = (int)(( y + 10 + 1) / H);
		cout << ans << endl;
	}


	return 0;
}

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

int main(){
	double v, y;cin >> v;
	y = 4.9 * pow(v / 9.8, 2);
	int n;
	for(n = 0;;n++){
		if(y <= 5*n-5)break;
	}
	cout << n << endl;
	return 0; 
}
//25.4
//32

C++: #include<iostream>
using namespace std;
int main(){
  double v,y,t;
  int n,h[100];
  for(int i=0; i<100; i++)
    h[i] = i*5-5;
  while(cin >> v){
    t = v/9.8;
    y = 4.9 * t * t;
    for(int j=0; j<100; j++){
      if(h[j] >= y){
	cout << j << endl;
	break;
      }
    }
  }
}

C++: #include "stdafx.h"
#include <iostream>
#include <string>
#include <stack>
#include <math.h>
#include <algorithm>
#include <cstdlib>
#include <ctime>
#include <vector>

using namespace std;





int main()
{
	double v;
	double h;
	int n = 1;
	while (cin >> v) {
		h = 4.9*(v / 9.8)*(v / 9.8);
		while (h > 5 * (n - 1)) {
			n++;
		}
		cout << n << endl;
	}


	return 0;
}

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

using namespace std;

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

  while(cin >> n){
    i = 1;
    while(1){
      y = 5 * (i - 1);
      t = sqrt(y / 4.9);
      v = 9.8 * t;
      if(n <= v) break;
      ++i;
    }
    cout << i << endl;
  }
  return 0;
}

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

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

C++: #include <iostream>

using namespace std;

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

    while (cin >> v) {
        t = v /9.8;
        y = 4.9 * t * t;
        n = 0;
        while(5 * n - 5 < y) n++;

        cout << n << endl;
    }

}

C++: #include<iostream>
#include<algorithm>
#include<cctype>
#include<cstring>
#include<cstdlib>
#include<vector>
#include<string>
#include<cmath>
using namespace std;
#define REP(i, j) for(int i = 0; i < j; i++)
#define FOR(i, j, k) for(int i = j; i < k; i++)
const double EPS = 1e-8;
const int INF = 1e9;

int main(){
    double vv;
    while(cin >>vv){
        double v = 0, t = 0, y;
        for(y = 0; v < vv; y += 5){
            t = sqrt(y / 4.9);
            v = 9.8 * t;
        }
        cout <<y / 5<<endl;
    }
    return 0;
}