I am a noob programmer but my I accepted a problem in CF global round 5. But in the main test got no verdict at that problem then I clicked on my profile submission and I saw runtime error in case no: 1 how this is possible? It comes runtime error in CF in the main test case 1 but in but pretest it was fine in pre-test. it also works fine in ideone. problem link https://codeforces.net/contest/1237/problem/B?statementsLocale=en my solution. https://ideone.com/prrXp7