class Solution {
    int res = 0;
    boolean[][] vis;

    public int movingCount(int m, int n, int k) {
        vis = new boolean[m][n];
        dfs(0, 0, m, n, k);
        return res;
    }

    void dfs(int x, int y, int m, int n, int k){
        if(x < 0 || x >= m || y < 0 || y >= n || vis[x][y] || !check(x, y, k)) return;
        res++;
        
        vis[x][y] = true;
        dfs(x + 1, y, m, n, k);
        dfs(x - 1, y, m, n, k);
        dfs(x, y + 1, m, n, k);
        dfs(x, y - 1, m, n, k);
    }

    boolean check(int x, int y, int k){
        return getNum(x) + getNum(y) <= k;
    }

    int getNum(int x){
        int res = 0;
        while(x != 0){
            res += x % 10;
            x /= 10;
        }
        return res;
    }
}