package main import . "fmt" func main() { var n int Scan(&n) if duel(n,0) { Println("Yes") } else { Println("No") } } var memo [1e5]int func duel(n, i int) bool { if i >= n { return n % 2 == 0 } if memo[i] != 0 { return memo[i] == 1 } won := 0 for x := 1; x <= 3; x++ { if !duel(n, i+x) { won++ } } if won > 0 { memo[i] = 1 } else { memo[i] = -1 } return won > 0 }