so i am beginer and just studying all this things and i would like to get help, if anyone can help me :) so there is the thing:
Programm looks like this:

program program1;
var a, b:integer;
begin
b:=0;
for a:=100 downto 1 do
b:=b+a;
writeln('number summ from 1 to 100 is: ',b);
readln;
end.

and i want to add to this program 1 feature; so how to get this program that it makes sum from 1 to 100 but doesnt counts in number which contains 7, like 7; 17; 37; 72 ...
so the thing is that i need to count all numbers (1 to 100) in summ but without those ones who contains 7

any help would be good :)