Răspuns:
a=72^2003+63^2003+54^2003+37^2003
u ( 72^2003+63^2003+54^2003+37^2003 )
u ( 72^2003 )= u ( 2^2003 )= u ( 2^4*500+3 )= u ( 2^3 )=8
u ( 63^2003 )= u ( 3^2003 )= u ( 3^4*500+3 )= u ( 3^3 )=7
u ( 54^2003 )= u ( 4^2003 )= u ( 4^2*1001+1 )=4
u ( 37^2003 )= u ( 7^2003 )= u ( 7^4*500+3 )= u ( 7^3 )=3
u ( a )= 8 + 7 + 4 + 3=22