use lists for compute sums with better precision,it actually can be improved with working in a 6 digits chunks that are treated as a 1 million base so the limits are breaked like 200.000 items limit because 6*200.000 turn 1.200.000
will explain the algorithm: we have two numbers like 372 more 893 372 893 first we sum the last digit after the penultimate digit and here we go 2 + 3 = 5 372 893 5 we summed the last digit so let's go to the penultimate 7 + 9 = 16 oops! override 9! so let's get the first digit(1) and ride it to the antipenultimate which it's called carry and for put it in the tens place use the last digit(6) 1 372 893 65 and the first digit 3 + 8 + 1(carry) = 12 wait, we can't put carry digit without digit to sum? no,simply put the carry 372 893 1265
