perl -e 'print STDOUT x x x + x x x;'

##</code><code>##

> perl -MO=Concise -e 'print x x x + x x x;'
c  <@> leave[t1] vKP/REFC ->(end)
1     <0> enter ->2
2     <;> nextstate(main 1 -e:1) v ->3
b     <@> print vKS ->c
3        <0> pushmark s ->4
5        <1> rv2gv sKR/1 ->6
4           <#> gv s ->5
a        <2> repeat[t2] sK/2 ->b
8           <2> repeat[t1] sK/2 ->9
6              <$> const(SPECIAL Null)[t4] s/BARE ->7
7              <$> const(SPECIAL Null)[t5] s/BARE ->8
9           <$> const(SPECIAL Null)[t6] s/BARE ->a
-e syntax OK

##</code><code>##

perl -e 'print STDOUT x x + 3;'