/*
 * Solution Template for Composing Pyramids
 * 
 * Australian Informatics Olympiad 2022
 * 
 * This file is provided to assist with reading of input and writing of output 
 * for the problem. You may modify this file however you wish, or
 * you may choose not to use this file at all.
 */

#include <cstdio>

/* N is the number of keys in the sequence. */
int N;

/* P contains the sequence of keys. */
int P[100005];

int answer;

int main(void) {
    /* Read the value of N. */
    scanf("%d", &N);

    /* Read the sequence of keys. */
    for (int i = 0; i < N; i++) {
        scanf("%d", &P[i]);
    }

    /*
     * TODO: This is where you should compute your solution. Store the minimum
     * number of keys you need to remove from the sequence into the variable
     * answer.
     */

    /* Write the answer. */
    printf("%d\n", answer);

    return 0;
}