。
Don't forget to count me in too.
Literal
Not-forget-[without-ず] me-[masculine-俺] [also-も] head-count [dat-に] include-[give-me-てくれ] [emphasis-よ]
Two masculine markers stacked: 俺 as the first-person pronoun, and ~てくれよ as the casual request. 頭数 (あたまかず) literally 'head-count' is used in the idiom 頭数に入れる = 'count in a headcount', i.e., include in a group for counting purposes. Note the compound is read with the kun reading あたま, not the on reading とう.