#include <iostream>
using namespace std;
float comma2Dot(string number)
{
for (int i=0; i<number.length(); i++)
if (number[i] == ',')
{
number[i] = '.';
break;
}
return stof(number);
}
int main()
{
string number_string;
cout << "Podaj liczbę (np. 3,14): ";
cin >> number_string;
float number = comma2Dot(number_string);
cout << "Twoja liczba to " << number << endl;
cout << "Twoja liczba podniesiona do kwadratu " << (number * number) << endl;
return 0;
}