[tex]n =67^{38}+ 92^{43} \\
u(n)=u(67^{38})+u(92^{43}) \\
u(n)=u(7^{38})+u(2^{43}) \\ \\
u(7^{38})=? \\
38:4=9~r~2 \\
Daca~restul~e~2,~il~ridici~pe~7~la~a~2a~si~iti~da~49. \\
u(7^{38})=u(7^2)=u(49)=9 \\ \\
u(2^{43})=? \\
43:4=10~r~3 \\
Daca~restul~e~3,~il~ridici~pe~2~la~a~3a~si~iti~da~8. \\
u(2^{43})=u(2^3)=u(8)=8 \\ \\
u(n)=u(9+8)=u(17)=\boxed{7}[/tex]
