int[] neighbours(int i,int j)
    {
        int cnt=0;
        int n[]=new int[4];
        if(i!=0)
        {
            if(!cells[i-1][j].visited) n[cnt++]=0;
        }
        if(j!=94)
        {
            if(!cells[i][j+1].visited) n[cnt++]=1;
        }
        if(i!=44)
        {
            if(!cells[i+1][j].visited) n[cnt++]=2;
        }
        if(j!=0)
        {
            if(!cells[i][j-1].visited) n[cnt++]=3;
        }
        int nb[]=new int[cnt];
        for(int k=0;k<cnt;k++) nb[k]=n[k];
        return nb;
    }