(let/cc e(let l()(let*((r read)(a(r))(b(r))(c(r))(z(if(eof-object? a)(e)))(s(/(+ a b c)2))(t(pa$ - s)))(print(inexact->exact(round(sqrt(*(t a)s(t b)(t c)))))))(l)))
Note that non-ascii characters in the above source code will be escaped (such as \x9f).