#include <string>
#include <iostream>
#include <fstream>


class Big
{
public:
	bool sign;
	int dig[15];
	
	Big() {for (int i = 0; i < 15; i++) dig[i] = 0;}
	Big(string &s)
	{
		for (int i = 0; i < 15; i++)
			dig[i] = 0;
		if (s[0] == '-')
			sign = true;
		else
			sign = false;
		int dp = 0;
		for (int i = s.length()-1; i >= 0; i--)
		{
			if (s[i] == '-')
				continue;
			dig[dp++] = s[i] - '0';
		}
	}
	
	void construct (string &s)
	{
		for (int i = 0; i < 15; i++)
			dig[i] = 0;
		if (s[0] == '-')
			sign = true;
		else
			sign = false;
		int dp = 0;
		for (int i = s.length()-1; i >= 0; i--)
		{
			if (s[i] == '-')
				continue;
			dig[dp++] = s[i] - '0';
		}
	}
	
	void overflow()
	{
		for (int i = 0; i < 15; i++)
		{
			while (dig[i] < 0)
			{
				dig[i] += 10;
				dig[i+1]--;
			}
			while (dig[i] >= 10)
			{
				dig[i] -= 10;
				dig[i+1]++;
			}
		}
	}
	
	bool abs_smaller (Big &b)
	{
		for (int i = 14; i >= 0; i--)
			if (dig[i] != b.dig[i])
				return dig[i] < b.dig[i];
		return false;
	}
	
	Big operator+ (Big &b)
	{
		Big res;
		if (sign == b.sign)
		{
			res.sign = sign;
			for (int i = 0; i < 15; i++)
			{
				res.dig[i] = dig[i] + b.dig[i];
			}
			res.overflow();
			return res;
		}
		if (abs_smaller (b))
		{
			res.sign = b.sign;
			for (int i = 0; i < 15; i++)
				res.dig[i] = b.dig[i] - dig[i];
		}
		else
		{
			res.sign = sign;
			for (int i = 0; i < 15; i++)
				res.dig[i] = dig[i] - b.dig[i];
		}
		res.overflow();
		return res;
	}
	
	Big &half()
	{
		for (int i = 0; i < 15; i++)
		{
			if ((dig[i] % 2) != 0)
				dig[i-1] += 5;
			dig[i] /= 2;
		}
		return *this;
	}
};

ostream &operator<< (ostream &out, Big b)
{
	if (b.sign)
		out << '-';
	bool zero = true;
	for (int i = 14; i >= 0; i--)
	{
		if (b.dig[i] != 0)
			zero = false;
		if (!zero)
			cout << b.dig[i];
	}
	return out;
}

Big x[1024];
Big y[1024];

int main()
{
	ifstream in("diplomatic.in");
while (true)
{
	int n;
	in >> n;
	if (!in.good())
		break;
	cout << n << ' ';
	Big tmp, xstart, ystart;
	string str;
	in >> str;
	xstart.construct(str);
	in >> str;
	ystart.construct(str);
	Big xlast, ylast, xact, yact;
	xlast = xstart;
	ylast = ystart;
	for (int i = 1; i < n; i++)
	{
		in >> str;
		xact.construct(str);
		in >> str;
		yact.construct(str);
		tmp = xact + xlast;
		cout << tmp.half() << ' ';
		tmp = yact + ylast;
		cout << tmp.half() << ' ';
		xlast = xact;
		ylast = yact;
	}
	tmp = xstart + xlast;
	cout << tmp.half() << ' ';
	tmp = ystart + ylast;
	cout << tmp.half() << endl;
}
	return 0;
}