checck and display the correspondence output

I have data like this

U_ID Ses_ID Deg
1 11 yes
1 12 yes
2 13 no
2 14 yes
3 15 no
4 16 yes
5 17 no
5 18 no
6 19 n/a
6 20 yes

I want output like this

Usr_ID Session ID Degree
1 11 yes
2 14 yes
3 15 no
4 16 yes
5 17 no
6 20 yes

explanation:
usr_ID was repeated more than once, but ses_ID are unique and one particular Usr_Id contain more than one degree if all degree are "yes" then show the degree as "yes", if one "yes", remaining "no" then display "yes" as degree but the correspondence ses_ID must be displayed with the Usr_ID