The integer variable n is not divisible by 3, so the condition is n%3! =0, as for the two-digit number without 3, then we have to separate the numbers in each position of this two-digit number and judge that it is not 3, then the expression is n% 10! = 0 & amp& ampn/ 10！ =0。 Then the combined expression is n%3! = & amp& ampn% 10！ = 0 & amp& ampn/ 10！ =0。