D.cpp

// #pragma GCC optimize("Ofast,unroll-loops")
// #pragma GCC target("avx,avx2,fma")

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define ull unsigned long long
#define dd double
#define ld long double
#define sl(n) scanf("%lld", &n)
#define si(n) scanf("%d", &n)
#define sd(n) scanf("%lf", &n)
#define pll pair <ll, ll>
#define pii pair <int, int>
#define mp make_pair
#define pb push_back
#define all(v) v.begin(), v.end()
#define inf (1LL << 61)
#define loop(i, start, stop, inc) for(ll i = start; i <= stop; i += inc)
#define for1(i, stop) for(ll i = 1; i <= stop; ++i)
#define for0(i, stop) for(ll i = 0; i < stop; ++i)
#define rep1(i, start) for(ll i = start; i >= 1; --i)
#define rep0(i, start) for(ll i = (start-1); i >= 0; --i)
#define ms(n, i) memset(n, i, sizeof(n))
#define casep(n) printf("Case %lld:", ++n)
#define pn printf("\n")
#define pf printf
#define EL '\n'
#define fastio std::ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);

// === Debug macro starts here ===

#ifndef ONLINE_JUDGE
#define DEBUG
#define SYS_COL system("COLOR")
#endif

int recur_depth = 0;
#ifdef DEBUG
#define dbg(x) {++recur_depth; auto x_=x; --recur_depth; SYS_COL; cerr<<string(recur_depth, '\t')<<"\e[91m"<<__func__<<":"<<__LINE__<<"\t"<<#x<<" = "<<x_<<"\e[39m"<<endl;}
#else
#define dbg(x)
#endif
template<typename Ostream, typename Cont>
typename enable_if<is_same<Ostream,ostream>::value, Ostream&>::type operator<<(Ostream& os,  const Cont& v){
	os<<"[";
	for(auto& x:v){os<<x<<", ";}
	return os<<"]";
}
template<typename Ostream, typename ...Ts>
Ostream& operator<<(Ostream& os,  const pair<Ts...>& p){
	return os<<"{"<<p.first<<", "<<p.second<<"}";
}

// === Debug macro ends here ===

const ll sz = 1e5 + 10;
ll ara[sz], lft[sz], rgt[sz];

int main()
{
    ll n, mxSeq = 0, cnt = 0;
    cin >> n;

    for1(i, n) sl(ara[i]);

    for1(i, n) {

        ll start = i, stop = i;

        for(ll j = i+1; j <= n; j++) {

            if(ara[j] > ara[j-1])
                break;

            stop = j;
        }

        for(ll j = start; j <= stop; j++)
            rgt[j] = stop;

        ll len = stop-i+1;

        if(mxSeq < len)
            mxSeq = len, cnt = 1;
        else if(mxSeq == len)
            cnt++;

        i = stop;
    }

    rep1(i, n) {

        ll start = i, stop = i;

        for(ll j = i-1; j >= 1; j--) {

            if(ara[j] > ara[j+1])
                break;

            stop = j;
        }

        for(ll j = start; j >= stop; j--)
            lft[j] = stop;

        ll len = i-stop+1;

        if(mxSeq < len)
            mxSeq = len, cnt = 1;
        else if(mxSeq == len)
            cnt++;

        i = stop;
    }

    ll ans = 0;

    for1(i, n) {

        ll l = (i-lft[i]+1), r = (rgt[i]-i+1);

        //dbg(l); dbg(r);

        if(max(l, r) <= 2)
            continue;

        ll mn = min(l, r), mx = max(l, r);

        if(mx<mxSeq)
            continue;

        if(mx==mxSeq && cnt > 2)
            continue;

        if(mn == mx && (mn&1))
            ans++;
    }

    cout << ans << EL;

    return 0;
}