/*
 * Solution Template for Laser Cutter
 * 
 * Australian Informatics Olympiad 2021
 * 
 * This file is provided to assist with reading and writing of the input
 * files 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 side length of the initial square. */
int N;

/* A contains the first sequence of instructions. */
char A[400005];

/* B contains the second sequence of instructions. */
char B[400005];

int answer;

int main(void) {
    /* Open the input and output files. */
    FILE *input_file = fopen("laserin.txt", "r");
    FILE *output_file = fopen("laserout.txt", "w");

    /*
     * Read the value of N and the sequences of instructions from the input
     * file.
     */
    fscanf(input_file, "%d", &N);
    fscanf(input_file, "%s", A);
    fscanf(input_file, "%s", B);

    /*
     * TODO: This is where you should compute your solution. Store the side
     * length of the largest square that fits inside the shape into the
     * variable answer.
     */

    /* Write the answer to the output file. */
    fprintf(output_file, "%d\n", answer);

    /* Finally, close the input/output files. */
    fclose(input_file);
    fclose(output_file);

    return 0;
}