Variables:
S::[0..9]
E::[0..9]
N::[0..9]
D::[0..9]
M::[0..9]
O::[0..9]
R::[0..9]
Y::[0..9]
Constraints:
1000*S + 100*E + 10*N + D    +    1000*M + 100*O + 10*R + E    =    10000*M + 1000*O + 100*N + 10*E + Y
S!=E
S!=N
S!=D
S!=M
S!=O
S!=R
S!=Y
E!=N
E!=D
E!=M
E!=O
E!=R
E!=Y
N!=D
N!=M
N!=O
N!=R
N!=Y
D!=M
D!=O
D!=R
D!=Y
M!=O
M!=R
M!=Y
O!=R
O!=Y
R!=Y