Prefix and Suffix

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

inputFormat

Input

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

N s t

outputFormat

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

样例

3
abc
cde

5