import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) throws FileNotFoundException {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int[] m = new int[n];
        for(int m_i=0; m_i < n; m_i++){
            m[m_i] = in.nextInt();
        }
        // your code goes here
        Solution s = new Solution();
        System.out.println(s.solve(n,m));
    }

	long solve(int n, int[] m) {
		int maxV = computeMaxV(0, m);
		
		long result = 0;
		for(int i = 1; i <= maxV; i++){
			result += solve(m, i, i);
		}
		return result;
	}

	long solve(int[] m, int i, int maxV) {
		if(m.length <= i) return 1;
		if(maxV == 1) return 1;
		if(lastStepCondition(m.length, i, maxV)) return computePositionPbLastStep(maxV,m.length-i);
		
		long result = 0;
		
		for(int j = 1; j <= maxV; j++){
			long result1 = computePositionPb(maxV,j);
			result += result1 * solve(m, i+j, j);
		}
		return result;
	}

	boolean lastStepCondition(int length, int i, int maxV) {
		return length - i - maxV <= 0;
	}

	long computePositionPb(int maxV, int j) {
		long result = 1;
		for(int i = 1, maxVRemain = maxV; i <= j; i++, maxVRemain--){
			result *= maxVRemain;
		}
		return result;
	}
	
	long computePositionPbLastStep(int maxV, int j) {
		return (long) Math.pow(maxV,j);
	}

	int computeMaxV(int i, int[] m) {
		if(i>= m.length)return 1; 
				
		int result = 1;
		int max = m[i];
		i++;
		for(; i<m.length;i++){
			if(m[i] > max)result++;
		}
		return result;
	}
}