Those 5 (five) countries that do NOT allow 1st cousins to marry are labeled.
A
B
C
-
China - Does not allow 1st cousin marriage
D
E
-
East Timor (Timor-Leste)
F
G
H
I
J
K
-
Korea, North - Does not allow 1st cousin marriage
L
M
-
Myanmar (Burma)
N
O
P
-
Philippines - Does not allow 1st cousin marriage
Q
R
S
T
-
Taiwan - Does not allow 1st cousin marriage
U
V
-
Vietnam - Does not allow 1st cousin marriage