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#include <iostream> #include <ctime> typedef long long ll; using namespace std; ll gt(int n){ if(n==0) return 1; return n*gt(n-1); } ll th(int k, int n){ ll s = 1; for(int i = n-k+1; i <= n; i++) s *= i; return s/gt(k); } int main(){ freopen("quick.inp","r",stdin); freopen("quick.out","w",stdout); int c, l = 0; int n; cin >> n; for(int i = 0; i < n; i++){ int t; cin >> t; if(t%2 != 0) ++l; } c = n-l; if(l%2 == 0) cout << th(2,c)+th(2,l) << endl; else cout << 1ll*c*l << endl; return 0; }
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