#include <iostream>
#include <string>   //for the standard library "string to integer" function stoi
#include <cstdlib>
using namespace std;

int main()
{
	for (;;) {
		cout << "Input an integer in binary (or control-d to end): ";
		string s;
		cin >> s;      //Attempt to input a string.
		if (!cin) {    //If attempt was unsuccessful (i.e., control-d)
			break; //out of the loop
		}

		try {
			const int i {stoi(s, nullptr, 2)};
			cout << "Binary " << s << " is decimal " << i << "\n\n";
		}

		catch (invalid_argument e) {
			//Arrive here if user typed characters other than 1 or 0
			cerr << "Sorry, in binary you can type "
				<< " only 1s and 0s.\n"
				<< "Try again.\n";
		}
	}

	cout << "\n";   //Arrive here when user typed control-d
	return EXIT_SUCCESS;
}