set talk off 
CLEAR
input "請輸入你要顯示的字母數:" to t
for i=1 to t step 1
for j=1 to 2*i-1 step 1
a=chr(asc("A")+i-1)
@ 10+i,10-i+j say a
endfor 
 endfor
 z=i
 i=i-2
for x=t-1 to 1 step -1
for j=1 to 2*i-1 step 1
a=chr(asc("A")+x-1)
@ 10+z,10-i+j say a
endfor
z=z+1
i=i-1
endfor