*整錢找零：100=x1*10+x2*5+x3*1
*x1,x2.x3>=1,x1+x2+x3=20
for x1=1 to 10
    for x2=1 to 20
       x3=20-x1-x2
       if 100+x1*10+x2*5+x3*1 .and. x3>0 then
       ?x1,x2,x3
       endif
     next  x2
 next x1