Code Corona

program bases_convt_dec (input, outpu);
var c:char; (* Convert number of Different bases to Decimal number *)
w:string;
count,base,err:integer;
z,b,pv : longint;

begin
write('Enter base :');
readln(base);
write('Enter number :');
readln(w);
pv:=1; (* value of unit digit *)
z:=0;
c:=w[length(w)];
case c of
'0'..'9' : val(c,b,err);
'A' : b:=10;
'B' : b:=11;
'C' : b:=12;
'D' : b:=13;
'E' : b:=14;
'F' : b:=15;
end;

z:=z+b;
for count:= length(w) - 1 downto 1 do begin
pv:= pv * base;
c:= w[count];
case c of
'0'..'9' : val(c,b,err);
'A' : b:=10;
'B' : b:=11;
'C' : b:=12;
'D' : b:=13;
'E' : b:=14;
'F' : b:=15;
end;
z:=z+(b*pv);
writeln('Decimal Result =',z);
end;
end.