#include <stdio.h>

int paren(int x) {
    if(x % 2 == 0) {
        return 1;
    }
    else {
        return 0;
    }
}
int main() {
    int n;
    scanf("%d", &n);
    int prethoden = 0;
    int brojac = 0;
    for(int i = 0; i < n; i++) {
        int x;
        scanf("%d", &x);

        if(prethoden != 0) {
            if(paren(x) && paren(prethoden)) {
                brojac++;
            }
            else if(!paren(x) && !paren(prethoden)) {
                brojac++;
            }
        }
        prethoden = x;

    }
    printf("%d\n", brojac);
    return 0;
}