#include <bits/stdc++.h>
#include <stdio.h>

using namespace std;

#define DEB(x) cout << #x << " = " << x << endl;

int p[1001][1001];

bool fK(int x1, int y1, int x2, int y2) {
    return (abs(x1 - x2) < 2 && abs(y1 - y2) < 2);
}

bool fN(int x1, int y1, int x2, int y2) {
    return (abs(x1 - x2) * abs(y1 - y2) == 2);
}

bool fB(int x1, int y1, int x2, int y2) {
    return (abs(x1 - x2) == abs(y1 - y2));
}

bool fR(int x1, int y1, int x2, int y2) {
    return (abs(x1 - x2) * abs(y1 - y2) == 0);
}

bool (*fch)(int, int, int, int) = NULL;

bool check(int ti, int tj) {
    for (int i = 0; i <= ti; i++) {
        for (int j = 0; j < tj; j++) {
            if (p[i][j] == p[ti][tj] && fch(i, j, ti, tj)) {
                return false;
            }
        }
    }
    return true;
}

int main(void) {
    int n;
    char c;
    while (scanf("%d %c", &n, &c) == 2) {
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                p[i][j] = 0;
            }
        }

        switch (c) {
            case 'R':
                fch = fR;
                break;
            case 'K':
                fch = fK;
                break;
            case 'B':
                fch = fB;
                break;
            case 'N':
                fch = fN;
                break;
        }


        int teams = 0;
        bool ok = false;
        while (!ok) {
            teams++;
            ok = true;
            for (int i = 0; i < n; i++) {
                for (int j = 0; j < n; j++) {
                    if (p[i][j] == 0) {
                        p[i][j] = teams;
                        if (!check(i, j)) {
                            p[i][j] = 0;
                            ok = false;
                        }
                    }
                }
            }
        }

        printf("%d\n", teams);
    }

    return 0;
}