Snuke is interested in strings that satisfy the following conditions:

• The length of the string is at least N.
• The first N characters equal to the string s.
• The last N characters equal to the string t.

Find the length of the shortest string that satisfies the conditions.

Constraints

• 1≤N≤100
• The lengths of s and t are both N.
• s and t consist of lowercase English letters.

Input

The input is given from Standard Input in the following format:

N
s
t

Output

Print the length of the shortest string that satisfies the conditions.

Examples

Input

3
abc
cde

Output

5

Input

1
a
z

Output

2

Input

4
expr
expr

Output

4

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