#include <iostream>
#include <sstream>
#include <string>
#include "rational7.h"
using namespace std;

// Input (extraction) operator for rational class
// This code uses conditional statement:
//    (bool-expression) ? expr_when_true : expr_when_false ;
istream& operator>> (istream& ins, rational& r)
{
	string s;
	bool isSlash = false, isNegative = false;
	bool isWhole = false;

	// Read a string (can read char by char, but less efficient).
	ins >> s;

	bool isValid = true;
	// Look at every character to see if it is valid
	for (int i = 0; i < s.length() && isValid; i++) 
	{
    	if (s[i] == '-')
		{ 
			// Must be at the beginning only
			isValid = ( i == 0) ? true : false;
			isNegative = (isValid) ? true : false;
		}
		else if (s[i] == '/')
		{
			// Must not be at the beginning or end or duplicated.
			isValid = (i == 0 || i == s.length()-1 || (i == 1 && isNegative ) || isSlash) ? false : true;
			isSlash = true;
		}
		else if (!isdigit(s[i])) {
			// Only valid characters are '-', '/'
			// and digits.
			isValid = false;
		}
	}

	// Set the failbit when not valid.
	if (isValid != true) {
		ins.setstate(ios::failbit);
		cerr << "Invalid rational" << endl;
		return ins;
	}

	// Smarter to use temporary variables because there can still be
	// an error with the denominator. We don't want to change the
	// rational if the read was unsucessful.
	int n, d;
	char c;
	istringstream str(s);
	if (isSlash) {
		str >> n >> c >> d;
	}
	else {
		str >> n;
		d = 1;
	}
	if (d == 0) {
		ins.setstate(ios::failbit);
		cerr << "Invalid rational" << endl;
		return ins;
	}
	r.set(n, d);
	return ins;
}

int main() {
	rational r1;
	cin >> r1;
}