N,M = map(int, input().split())
if N>2:
    print(0)
    exit()
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))