logic - Find the sum of all the natural numbers not divisible by three between one and 3¹⁰⁰⁰⁰⁰

What is the easiest way to find the sum of all the numbers

$1, 2, 3, ..., 3¹⁰⁰⁰⁰⁰$ that are not divisible by 3,

possibly by using a handheld calculator and avoiding computer processing?