#include <iostream>
#include <sstream>
#include <math.h>
#include <stack>
#include <set>
#include <algorithm>
#include <string>
#include <queue>
#include <stack>
#include <map>
#include <cstdio>
#include <vector>
using namespace std;

#define INF (1 << 30)
#define INFLL (1LL << 60)

int main() {
	int n,k,ans = 0;
	bool be;
	for(int i = 0;i < 1000;i++){
		cin >> n >> k;
		if(i > 0) {
			if(be == 1) be = 0;
			else {
				ans++;
				be = 1;
			}
		}
		if(i == 0 && n % 2 == 0) {
			ans++;
			be = 1;
		}else if(i == 0 && n % 2 == 1){
			be = 0;
		}
	}
	cout << ans << endl;
	return 0;
}