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#include <bits/stdc++.h>
using namespace std;
int t[50001];
int t2[50001];
int n, z, r, w, m, w2;

int main()
{
    cin >> n;
    for (int i=1;i<=n;i++)
    {
        cin >> t[i];
        t2[i]=t[i];
    }
    z=2;

    if(t[1]==t[2])
    {
        t[2]=(1<<20);
        t2[2]=-(1<<20);
        w++;
        w2++;
    }
    else
    {
        if(t[1]<t[2]) {w2++; t2[2]=-(1<<20);}
        else {w++; t[2]=(1<<20);}
    }
    for (int i=3;i<=n;i++)
    {
        if(t[i-1]>=t[i] && z%2==1) {w++; t[i]=(1<<20);}
        if(t[i-1]<=t[i] && z%2==0) {w++; t[i]=-(1<<20);}

        if(t2[i-1]<=t2[i] && z%2==1) {w2++; t2[i]=-(1<<20);}
        if(t2[i-1]>=t2[i] && z%2==0) {w2++; t2[i]=(1<<20);}

        z++;
    }

    cout << min(w, w2);


}