Obfuscation S47315

Obfuscation of a string s = c₁ c₂ c₃ … c_k with respect to a natural number n consists of changing all the letters c_i ∈ s by the letter that is n places after c_i in the alphabet.

For example, ofuscacio(1,'A') = 'B', because 'B' is one place after 'A'. Other examples: ofuscacio(4,'B') = 'F' and ofuscacio(2,'AB') = 'CD'.

The function recursive void ofuscacio(int n, string s) must be implemented with the following specification:

PRE: The input is an integer n such that 0 ≤ n ≤ 20 and a string of characters s = c₁ c₂ c₃ … c_k such that k > 0 and ∀ c_i ∈ s, ′A′ ≤ c_i ≤ ′F′.

POST: writes to the output channel cout the obfuscation of the string of characters s with respect to n.

Observation

If necessary, you can use the method pop_back() for vectors and string.

Only recursive solutions are accepted.

Just send the function. The rest will be ignored.

Input

An integer n such that 0 ≤ n ≤ 20 and a string of characters s = c₁ c₂ c₃ … c_k such that k > 0 and ∀ c_i ∈ s, ′A′ ≤ c_i ≤ ′F′.

Output

For each pair n, s, the obfuscation of s with respect to n.