ARTIFICIAL
NATURAL
SOURCES
VISION
CANDLE
LIGHT
FIRE
IPAD
SUN
TV
W
N
Y
O
F
I
R
E
C
C
Z
Q
I
J
A
T
C
H
F
K
S
J
U
U
V
U
H
T
D
F
I
V
Y
L
Z
I
I
O
I
I
U
E
E
N
J
T
A
O
I
A
X
U
I
R
U
A
R
L
J
I
M
L
P
L
O
T
A
X
Z
V
E
R
C
C
C
U
A
G
T
L
H
V
E
I
K
I
E
E
G
P
D
R
Q
E
N
L
O
S
F
W
N
E
L
O
T
E
Y
G
D
L
T
I
U
F
K
I
C
V
U
V
I
N
S
X
T
O
O
O
G
C
O
N
X
Z
A
M
F
R
K
N
G
H
R
C
U
E
U
C
I
I
A
O
J
E
T
Y
G
S
O
U
R
C
E
S
Y
B
G
A
E
