Assume that the following XML code is written for ordering a party pizza online from a pizza restaurant:

$$ item $>$ size$>$party $<mtext></mtext><mi>/</mi>$size$>$ price$>$$$59\mathrm{.}99<mtext></mtext><mi>/</mi>$price$>$ quantity $>1<mtext></mtext><mi>/</mi>$quantity$><mtext></mtext><mi>/</mi>$item$>$

You can attempt SAX Injection attack to get one party pizza at $$9\mathrm{.}99.$ Instead of filling in $1$ on the purchase order form, what should you fill in$?$