C :

#include <string.h>

int main(int argc, char* argv[])
{
	char a[100];

	scanf("%s",a);
	
	int length=strlen(a);
	
	while (a[length-1] =='0')
	{
		length--;
		continue;
	}
	if (a[0]=='-'){
		printf("%c",a[0]);
	    for(int k=length-1;k>0;k--)
		{
	       printf("%c",a[k]);
		}
	}

   else
   {
	for(int k=length-1;k>=0;k--)
		{
	    printf("%c",a[k]);
	}
   }

	
    printf("\n");

	return 0;
}

C++ :

#include<iostream>
#include<cstring>
using namespace std;
int main()
{
	char a[12];
	cin>>a;
	int len=strlen(a);
	char t;
	 int x;
	 for(int i=len-1;i>=0;i--)
	 	if(a[i]=='0')
	 		continue;
	 	else 
	 	  {
		     x=i;
		     break;
	 	  }
      for(int i=x;i>=0;i--)
      	if(a[0]!='-')
          	  cout<<a[i];
         else
           {
           		cout<<'-';
           		for(int i=x;i>=1;i--)
          		cout<<a[i];
          		break;
           }
      return 0;
		
}

Pascal :

var
st:string;
t:char;
flag:boolean;
len,i:longint;
begin
readln(st);
if st[1] = '-' then
begin
flag:=true;
delete(st,1,1);
end
else flag := false;
len := length(st);
for i := 1 to len div 2 do
begin
t := st[i];
st[i] := st[len - i + 1];
st[len - i + 1] := t;
end;
while (st[1] = '0') and (length(st) > 1) do delete(st,1,1);
if flag then st := '-' + st;
writeln(st);
end.