from collections import defaultdict
from functools import lru_cache
from sys import flags, stdin
import math
import re
import queue
import typing
import itertools
import bisect
import statistics
# import numpy as np
# from numpy.core.function_base import _needs_add_docstring
# from numpy.core.numeric import outer
input = stdin.readline
MOD = 1000000007
INF = 122337203685477580


def solve():
    n, m = map(int, input().split())
    if n > 2:
        print(0)
        return
    a = input()
    b = input()
    # print(a[1:-1])
    # print(b[:-2])
    if a[1:-1] == b[:-2] and b[1:-1] == a[:-2]:
        print(2)
    elif a[1:-1] == b[:-2] or b[1:-1] == a[:-2]:
        print(1)
    else:
        print(0)

    return


if __name__ == '__main__':
    solve()