C :

#include <stdio.h>

int main(){
    int i,n,s = 0;
    scanf("%d",&n);
    for(i = 1;i <= n;i = i + 2){
       s = s + i;
    }
    printf("%d\n",s);
    
    return 0;
}

C++ :

#include <bits/stdc++.h>

using namespace std;

int main(){
    int n;
    cin>>n;
    int i,c=0;
    for(i=1;i<=n;i=i+2){
        c=c+i;	
	}cout<<c<<endl;
    return 0;
}

Pascal :

var n,i,sum,x:longint;    max,min,pjf:longint; k,ooo:real;
begin
   readln(x);
   while i<x do
   begin
      i:=i+1;
      if i mod 2=1 then sum:=sum+i;
   end;
   writeln(sum); 
end.

Java :

import java.util.Scanner;
public class Main {
	public static void main(String[] args){
		Scanner in = new Scanner(System.in);
		int n = in.nextInt();
		int x =0;
		for(int i=1; i<=n;i++ ){
			if(i%2!=0)
				x=x+i;
		}
		System.out.println(x);		
	}
}

Python :

n =  int(input());
s = 0;
for i in range(1,n + 1):
    if i % 2 == 1:
      s = s + i;
print(s);