# get values for 3 numbers
a = ...
b = ...
c = ...
# move the lowest value to "a"
if a > b:
a,b = b,a #swap a and b
if a > c:
a,c = c,a # swap a and c
# move the next lowest value to "b"
if b > c:
b,c = c,b # swap b and c
# ...the highest value is now in "c"