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#include <bits/stdc++.h>
#include <iostream>

//#define TEST

using namespace std;

#define FAST  ios_base::sync_with_stdio(0) ;cin.tie(0);

#define pb push_back
#define mp make_pair

#define fi(a, b) for(int i=a; i<=b; i++)
#define fj(a, b) for(int j=a; j<=b; j++)
#define fo(a, b) for(int o=a; o<=b; o++)

#define fdi(a, b) for(int i=a; i>=b; i--)
#define fdj(a, b) for(int j=a; j>=b; j--)
#define fdo(a, b) for(int o=a; o>=b; o--)

#define sz(x) (int)x.size()

#define init_v( tab, n ) fo(1, n ) tab.pb(0)

typedef long long ll;
typedef long double ld;
typedef vector <int> vi;
typedef pair <int, int> pii;
typedef vector <pii> vpii;
typedef pair <ll, ll> pll;
typedef vector <pll> vpll;
typedef vector <ll> vll;

template <typename T> ostream& operator<<( ostream& os, vector<T> v)
{
    fi(0, sz(v) - 1)   os << v[i] << " ";
    return os;
}
template <typename A, typename B> ostream& operator <<(ostream& os, pair< A, B> p)
{
    os << "(" << p.first << ", " << p.second << ")";
    return os;
}
template <typename T> ostream& operator<<( ostream& os, set<T> t)
{
    for (auto z : t)
    {
        os << z << " ";
    }
    return os;
}
template <typename T1, typename T2> ostream& operator <<(ostream& os, map< T1, T2> t)
{
    cerr << endl;
    for (auto z : t)
    {
        os << "\t" << z.first << " -> " << z.second << endl;
    }
    return os;
}

#ifdef TEST
#define dbg(x) {cerr << __LINE__ << "\t" << #x << ": " << x << endl;}
#define dbg0(x, n) {cerr << __LINE__ << "\t" << #x << ": "; for (int ABC = 0; ABC < n; ABC++) cerr << x[ABC] << ' '; cerr << endl;}
#else
#define dbg(x) ;
#define dbg0(x, n) ;
#endif

void przekierowanie()
{
#ifdef TEST
    freopen( "input.txt", "r", stdin );
    freopen( "output.txt", "w", stdout );
#endif
}
#define MODULO 1000000007

ll power_modulo_fast(ll a, ll b)
{
    ll i;
    ll result = 1;
    ll x = a%MODULO;

    for (i=1; i<=b; i<<=1)
    {
        x %= MODULO;
        if ((b&i) != 0)
        {
            result *= x;
            result %= MODULO;
        }
        x *= x;
    }
    return result;
}

int main()
{
    FAST
    przekierowanie();


    long n;
    cin >> n;
    vll tab( n );
    for( long i = 0; i < n; i ++ )
        cin >> tab[ i ];

    long l_parzystych = 0;
    long i = 0;
    bool wsk = true;
    while( i < n )
    {
        while( i <n && tab[ i ] % 2 == 0)
        {
            l_parzystych ++;
            i ++;
        }
        if( i < n )
        {
            i ++;
            while( i < n && tab[ i ] % 2 ==0 )
                i ++;
            if( i < n )
                l_parzystych ++;
            else
                wsk = false;
        }
        i ++;
    }

//   cout << wsk << endl;
//   cout << l_parzystych << endl;

    if( wsk == false )
        cout << 0 << '\n';
    else
    {
        ll wynik = power_modulo_fast( 2, l_parzystych - 1 );
        cout << wynik << '\n';
    }

    return 0;
}