#include <bits/stdc++.h>
using namespace std;
#define sz(x) ((int)x.size())
const int maxn = 250000 + 5;
#define  _ <<" " <<
int n, m, k;

struct DSU {
    vector<int> fa, s;
    int cnt; // connect area number
    DSU(int n=1) : fa(n+1,-1), s(n+1,1), cnt(n) {}
    int size(int x) { return s[find(x)]; }
    int find(int x) { return -1 == fa[x] ? x : fa[x] = find(fa[x]); }
    bool connect(int x, int y) {
        x = find(x), y = find(y);  
        if (x == y) return false;
        if (s[x] > s[y]) swap(x, y);
        cnt--; s[y] += s[x]; 
        fa[x] = y;
        return true;
    }
};

DSU dsux, dsuy, dsuxpy, dsuxmy;

int getid(int x,int y) {
    return (y-1)*n + x;
}
vector<int> h[maxn];

bool hasb(int x,int y, int player) {
    if (x < 1 || x > n || y < 1 || y > m) return false;
    return h[x].size() >= y && h[x][y-1] % 2 == player;
}

void connect(int x,int y,int player,int tim) {
    int id = getid(x,y);

    if (hasb(x+1,y,player)) dsux.connect(id, getid(x+1,y));
    if (hasb(x-1,y,player)) dsux.connect(id, getid(x-1,y));

    if (hasb(x,y-1,player)) dsuy.connect(id, getid(x,y-1));

    if (hasb(x-1,y-1,player)) dsuxpy.connect(id, getid(x-1,y-1));
    if (hasb(x+1,y+1,player)) dsuxpy.connect(id, getid(x+1,y+1));

    if (hasb(x+1,y-1,player)) dsuxmy.connect(id, getid(x+1,y-1));
    if (hasb(x-1,y+1,player)) dsuxmy.connect(id, getid(x-1,y+1));

    // cout << x _ y _ dsuxmy.size(id) << endl;
    if (dsux.size(id) >= k || dsuy.size(id) >= k || 
      dsuxmy.size(id) >= k || dsuxpy.size(id) >= k) {
        if (player) {
            cout << "A" _ tim << '\n';
            exit(0);
        } else {
            cout << "B" _ tim << '\n';
            exit(0);
        }
      }
}

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
   
    cin >> m >> n >> k;
    dsux = DSU(getid(n+1,m+1)); dsuy = DSU(getid(n+1,m+1));
    dsuxpy = DSU(getid(n+1,m+1)); dsuxmy = DSU(getid(n+1,m+1));

    vector<int> q(n*m+1);
    for (int i = 1;i <= n*m; ++i) cin >> q[i];
    for (int i = 1;i <= n*m; ++i) {
        int c = q[i];
        h[c].push_back(i&1);
        connect(c, sz(h[c]), i&1, i);
    }
    cout << "D" << endl;
    return 0;
}