#include <bits/stdc++.h>
using namespace std;
double a;
int main()
{
cin>>a;
cout<<fixed<<setprecision(2)<<a*a;
return 0;
}
program hinhvuong;
uses crt;
var a,s:real;
begin
clrscr;
write('Nhap do dai canh a: ');
readln(a);
if (a>0) then
begin
s:=a*a;
write('Dien tich hinh vuong do la: ',s:1:2);
end;
readln;
end.