[t107] Secret Problem

#include <bits/stdc++.h>

using namespace std;

const int N = 1010;

int main()
{
    int n, k;
    char s[N];
    scanf("%d%d %s", &n, &k, s);
    k %= 26;
    if (k < 0) k += 26;

    for (int i = 0; s[i]; ++i) {
        if (isupper(s[i]))
            s[i] = ((s[i]-'A')+k)%26 + 'A';
        else if (islower(s[i]))
            s[i] = ((s[i]-'a')+k)%26 + 'a';
        printf("%c", s[i]);
    }

    return 0;
}