#include <iostream>
#include <string>

int main()
{
	std::string s = "10";

	int i = 0;
	for (char c: s)
	{
		if (c >= '0' && c <= '9') {
			i = i * 10 + (c - '0');
		}
		else {
			std::cout << "Bad Input";
			return 1;
		}
	}

	std::cout << i << '\n';

	return 0;
}