Hi to all!
Another option (With Microsoft 365) could be:
=LET(o,SORT(A3:B18,{1;2},{1;-1}),s,"|",
f,LAMBDA(t,p,TEXTBEFORE(t,p)),g,LAMBDA(t,p,TEXTAFTER(t,p)),n,INDEX(o,,1),
a,--MAP(SCAN("|0",n&s&INDEX(o,,2),LAMBDA(i,x,f(x,s)&s&(f(i,s)=f(x,s))*g(i,s)+g(x,s))),LAMBDA(n,g(n,s)))...