I ['I1', 'I2', 'I3', 'I4']
A ['A1', 'A2', 'A3']
U
U[I1,A1] 1.3
U[I1,A2] 2.3
U[I1,A3] 3.3
U[I2,A1] 1.4
U[I2,A2] 2.4
U[I2,A3] 3.4
U[I3,A1] 1.5
U[I3,A2] 2.5
U[I3,A3] 3.5
U[I4,A1] 1.6
U[I4,A2] 2.6
U[I4,A3] 3.6
