plot(c(-0,25),c(15,60),type="n",xlab="",ylab="",asp=1/2)
R <- 12; C <- 40
for(L in 1:20) for(i in 1:L) {
t <- L-floor(L/4)*4;
if(t==0) C <- C+2;
if(t==1) R <- R+1;
if(t==2) C <- C-2;
if(t==3) R <- R-1;
text(R,C,"#") }