Both of the two coders went to the same grade of the same high-school. Students in the school often uses "the N-th class" to express the grade and the graduation year (whether they are competitive programmers or not.) They were the 58th class student, so they use '58' as a suffix...
There is either the suffix -er at the end of the adjective (when two items are being compared), or the suffix -est if the comparison contains more than one item. Comparisons can also involve aspects such as quantity and number using expressions like more, fewer, less and another. The ...