input: [1] bus [2] fill [3] Boyd [4] side [5] off [6] fish [7] beg [8] heat [9] fell [10] dad [11] key [12] hate [13] bath [14] tie [15] house [16] hit [17] on [18] duck [19] full [20] cow [21] mice [23] go [24] choice [25] pest [26] heed [27] tape [22] 
output: sock