Welcome to [Biweekly Contest 77](/contest/biweekly-contest-77)! Feel free to share and post your contest experience here!\n\nYou can also view the rankings for the contest [here](/contest/biweekly-contest-77/ranking).\n\nLinks to the individual problems are included below:\n\n[Count Prefixes of a Given String](/problems/count-prefixes-of-a-given-string) (3 points)\n\n[Minimum Average Difference](/problems/minimum-average-difference) (4 points)\n\n[Count Unguarded Cells in the Grid](/problems/count-unguarded-cells-in-the-grid) (5 points)\n\n[Escape the Spreading Fire](/problems/escape-the-spreading-fire) (6 points)\n\n----\n\n\n<p style="color: red">\n\u2753 Do you enjoy the contest? \nClick <a href="https://form.nativeforms.com/kESMZTWW1jZmMDevRTNw0Db" target="_blank">\uD83D\uDC49 HERE\uD83D\uDC48 </a> to fill out a quick survey and help LeetCode provide a better contest experience.\n</p>

Welcome to Biweekly Contest 77! Feel free to share and post your contest experience here!\n\nYou can also view the rankings for the contest here.\n\nLinks to th