/*
 * Solution Template for Making Bank
 * 
 * Australian Informatics Olympiad 2023
 * 
 * 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 <stdio.h>

/* N is the number of days. */
int N;

/* days contains the type of each day. */
char days[100005];

int answer;
int main(void) {
    /* Read the value of N and the string of characters. */
    scanf("%d", &N);
    scanf("%s", days);

    /*
     * TODO: This is where you should compute your solution. Store the most
     * money that you can retire with into the variable answer.
     */

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

    return 0;
}