cp big1.txt big4.txt
cp big2.txt big5.txt
cp big3.txt big6.txt

cp big1.txt big7.txt
cp big2.txt big8.txt
cp big3.txt big9.txt

cp big1.txt biga.txt
cp big2.txt bigb.txt
cp big3.txt bigc.txt

cp big1.txt bigd.txt
cp big2.txt bige.txt
cp big3.txt bigf.txt

cp big1.txt bigg.txt
cp big2.txt bigh.txt
cp big3.txt bigi.txt

cp big1.txt bigj.txt
cp big2.txt bigk.txt
cp big3.txt bigl.txt

cp big1.txt bigm.txt
cp big2.txt bign.txt
cp big3.txt bigo.txt

cp big1.txt bigp.txt
cp big2.txt bigq.txt
cp big3.txt bigr.txt

cp big1.txt bigs.txt
cp big2.txt bigt.txt
cp big3.txt bigu.txt