Program na obliczanie pola kwadratu

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# include <iostream>
# include <cstdio>
using namespace std;
int main ( );
{
gloat bok;
do
{
cout << "dodatnia dlugosc boku";
cin >> bok;
if ( bok < = 0 )
cout  "niepoprawna dlugosc boku";
<< endl;
}
while ( bok > 0 )
cout << "Pole kwadratu wynosi:";
<< bok * bok;
cin.ignore ( );
getchar ( );
return 0;
}