matrr amtrr mtarr tmarr atmrr tamrr martr amrtr mratr rmatr armtr ramtr mtrar tmrar mrtar rmtar trmar rtmar atrmr tarmr artmr ratmr tramr rtamr matrr amtrr mtarr tmarr atmrr tamrr martr amrtr mratr rmatr armtr ramtr mtrar tmrar mrtar rmtar trmar rtmar atrmr tarmr artmr ratmr tramr rtamr marrt amrrt mrart rmart armrt ramrt marrt amrrt mrart rmart armrt ramrt mrrat rmrat mrrat rmrat rrmat rrmat arrmt rarmt arrmt rarmt rramt rramt mtrra tmrra mrtra rmtra trmra rtmra mtrra tmrra mrtra rmtra trmra rtmra mrrta rmrta mrrta rmrta rrmta rrmta trrma rtrma trrma rtrma rrtma rrtma atrrm tarrm artrm ratrm trarm rtarm atrrm tarrm artrm ratrm trarm rtarm arrtm rartm arrtm rartm rratm rratm trram rtram trram rtram rrtam rrtam
Note: these 'words' (valid or invalid) are all the permutations of the word matrr. These words are obtained by scrambling the letters in matrr.