import bisect def main(): import sys input = sys.stdin.read data = input().split() N = int(data[0]) P = list(map(int, data[1:N+1])) cross = [[0] * (N + 1) for _ in range(N + 1)] for j in range(N + 1): if j == 0: sorted_j = [] else: sorted_j = sorted(P[:j]) current = 0 for i in range(j + 1, N + 1): if j == 0: cross[j][i] = 0 continue val = P[i - 1] cnt = len(sorted_j) - bisect.bisect_right(sorted_j, val) current += cnt cross[j][i] = current dp = [[float('inf')] * (N + 1) for _ in range(N + 2)] for i in range(N + 1): dp[1][i] = 0 for m in range(2, N + 2): for i in range(1, N + 1): for j in range(i): if dp[m-1][j] + cross[j][i] < dp[m][i]: dp[m][i] = dp[m-1][j] + cross[j][i] for k in range(1, N + 1): m = k + 1 if m > N + 1: print(dp[N+1][N]) else: print(dp[m][N]) if __name__ == "__main__": main()