#!/usr/local/bin/python3

r=[5, "APPLE", "LEAPP"]
num=int(r[0])
total=0
model=[]
target=[]
for i in range(num):
    model.append(r[1][i])
    target.append(r[2][i])
def sorten(total):
    for i in range(num):
        if model[i]!=target[i]:
            moji=target[0]
            target.pop(0)
            target.append(moji)
            total+=1
            sorten(total)
    print(total)
sorten(total)