C :

#include<stdio.h>
int main()
{   
	int n;
	scanf("%d",&n);
	if(n==1)
	      printf("January\n");
	if(n==2)
	      printf("February\n");
	if(n==3)
	      printf("March\n");
	if(n==4)
	      printf("April\n");
	if(n==5)
	      printf("May\n");
	if(n==6)
	      printf("June\n");
	if(n==7)
	      printf("July\n");
	if(n==8)
	      printf("August\n");
	if(n==9)
	      printf("September\n");
	if(n==10)
	      printf("October\n");
	if(n==11)
	      printf("November\n");
	if(n==12)
	      printf("December\n");
		
}

C++ :

#include <stdio.h>
int main() {
	char *months[] = {"January", "February", "March",
		"April", "May", "June", "July", "August", "September",
		"October", "November", "December"};
	int month;
	scanf("%d", &month);
	printf("%s\n", *(months + month - 1));
	return 0;
}

Pascal :

var
  n:longint;
begin
  readln(n);
  case n of
  1:writeln('January');
  2:writeln('February');
  3:writeln('march');
  4:writeln('April');
  5:writeln('may');
  6:writeln('June');
  7:writeln('July');
  8:writeln('August');
  9:writeln('September');
  10:writeln('October');
  11:writeln('November');
  12:writeln('December');
  end;
end.

Java :

import java.util.Scanner;

public class Main {
   private static Scanner s = new Scanner(System.in) ;
   
   public static void main(String[] args) {
	  int month = s.nextInt() ;
	  System.out.println(get(month));
   }
   
   public static String get(int month){
	   String str = "" ;
	   if(month==1){
		   str = "January" ;
	   }
	   else if(month==2){
		   str = "February" ;
	   }
     else if(month==3){
    	 str = "March" ;
     	   }
     else if(month==4){
    	 str = "April " ;
     }
     else if(month==5){
    	 str = "May" ;
     }
     else if(month==6){
    	 str = "June" ;
     }
     else if(month==7){
    	 str = "July" ;
     }
     else if(month==8){
    	 str = "August" ;
     }
     else if(month==9){
    	 str = "September" ;
     }
     else if(month==10){
    	 str = "October " ;
     }
     else if(month==11){
    	 str = "November" ;
     }
     else if(month==12){
    	 str = "December" ; 
     }
	   return str ;
   }
}