Connected Cells in a Grid

#include<iostream>
using namespace std;
struct toaDo {
    int x, y;
};
int X[8] = {0,-1,0,1,-1,-1,1,1};
int Y[8] = {-1,0,1,0,-1,1,1,-1};
int main()
{
    //freopen("input.txt", "r", stdin);
    int n, m;
    cin >> n >> m;
    int A[11][11];
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < m; j++)
        {
            cin >> A[i][j];
        }
    }
    toaDo QQ[100];
    int front = -1, rear = -1, res=0;
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < m; j++)
        {
            int count = 0;
            if (A[i][j] == 1)
            {
                struct toaDo D;
                D.x = i;
                D.y = j;
                rear = (rear + 1) % 100;
                QQ[rear] = D;
                count += 1;
                A[i][j] = 0;
                while (front != rear)
                {
                    toaDo E;
                    front = (front + 1) % 100;
                    E.x = QQ[front].x;
                    E.y = QQ[front].y;
                    for (int direct = 0; direct < 8; direct++)
                    {
                        toaDo F;
                        F.x = E.x + X[direct];
                        F.y = E.y + Y[direct];
                        if (F.x >= 0 && F.x < n && F.y >= 0 && F.y < m && A[F.x][F.y] == 1)
                        {
                            rear = (rear + 1) % 100;
                            QQ[rear] = F;
                            A[F.x][F.y] = 0;
                            count += 1;
                        }
                    }
                }
                if (res < count) res = count;
            }
        }
    }
    cout << res;
    return 0;
}