typedef struct{float x,  y;} seg;
seg s[] = {{0, 1}, {1, 0}, {0.7, 0.6}};
void pl(char * k){double x=0, y=0;
  plot(x, y);
  while(* k){
    if(*k<'A' ||*k >'H') exit(printf("Poo\n"));
    int n = *k-'A', j=n/2, o=n&1?-1:1;
    x += o*s[j].x; y += o*s[j].y; ++k;
    plot(x, y);}}