Get 3 integers from the user
Read and save the integers as n1,n2,n3
Set n1=mid_value
IF (n1<n2 AND n1<n3) OR (n1>n2 AND n1>n3) THEN
Set n2=mid_value
ELSE IF (n2>n1 AND n2>n3) OR (n2<n1 AND n2<n3) THEN
Set n3=mid_value
Print ("the middle value is ____", mid_value)