class FenwickTree: def __init__(self, size): self.n = size self.tree = [0] * (self.n + 2) # Use 1-based indexing def update(self, idx, delta=1): while idx <= self.n: self.tree[idx] += delta idx += idx & -idx def query(self, idx): res = 0 while idx > 0: res += self.tree[idx] idx -= idx & -idx return res def main(): import sys input = sys.stdin.read data = input().split() n = int(data[0]) p = list(map(int, data[1:n+1])) if n == 0: print(1) return # Precompute factorials up to (n-1)! max_fact = n - 1 fact = [1] * (max_fact + 1) for i in range(1, max_fact + 1): fact[i] = fact[i - 1] * i ft = FenwickTree(n) for i in range(1, n + 1): ft.update(i) result = 0 for i in range(n): current = p[i] # Number of available elements less than 'current' count = ft.query(current - 1) # Factorial term (n - i - 1)! if (n - i - 1) >= 0: factorial = fact[n - i - 1] else: factorial = 1 result += count * factorial # Mark 'current' as used ft.update(current, -1) print(result + 1) if __name__ == "__main__": main()