N,M = map(int, input().split())
if N>3:
    print(0)
    exit()
if N==3:
    print(1)
if N==2:
    S1 = input()
    S2 = input()
    ANSSET = set()
    T1 = S1[0]+S2
    if T1[:M]==S1:
        ANSSET.add(T1)
    T2 = S2[0]+S1
    if T2[:M]==S2:
        ANSSET.add(T2)


    for i1 in range(M):
        if S1[i1]!=S2[i1]:
            break
    for i2 in reversed(range(M)):
        if S1[i2]!=S2[i2]:
            break
    if i1==i2 and 0<i1<M-1:
        print(1+len(ANSSET))
    else:
        print(0+len(ANSSET))