Let L (xe(a,b)' | Na (x) Nb(x)) where Nc (x) denotes the number of c's in x. A grammar for L with start symbol E can be written as EaEbEbEaEIA. With this grammar, we can construct a grammar for the following language as However, s EaES | is not a grammar for L1. In the following blank, give a string that cannot be generated by the first grammar (S EaET T aETI ), but can be generated by the second one (S EaES | ). (1 point)