# need help! simple counting programm

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);
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

• Why do you count down instead of up?
[code]
program program2;
var
a, b:integer;
begin
b:=0;
for a:=100 downto 1 do begin
if (a mod 10) = 7 then
continue ;
if ((a div 10) mod 10) = 7 then
continue ;
b:=b+a
end ;
writeln('number summ from 1 to 100 is: ',b) ;
end.
[/code]
If you have an older Pascal that does not support [b]continue[/b] then
[code]
program program3;
var
a, b:integer;
flag1,
flag2 : boolean ;
begin
b:=0;
for a:=100 downto 1 do begin
flag1 := ((a mod 10) = 7) ;
flag2 := (((a div 10) mod 10) = 7) ;
if (not flag1) and (not flag2) then
b:=b+a
end ;
writeln('number summ from 1 to 100 is: ',b) ;
end.
[/code]
• Why do you count down instead of up?
[code]
program program2;
var
a, b:integer;
begin
b:=0;
for a:=100 downto 1 do begin
if (a mod 10) = 7 then
continue ;
if ((a div 10) mod 10) = 7 then
continue ;
b:=b+a
end ;
writeln('number summ from 1 to 100 is: ',b) ;
end.
[/code]
If you have an older Pascal that does not support [b]continue[/b] then
[code]
program program3;
var
a, b:integer;
flag1,
flag2 : boolean ;
begin
b:=0;
for a:=100 downto 1 do begin
flag1 := ((a mod 10) = 7) ;
flag2 := (((a div 10) mod 10) = 7) ;
if (not flag1) and (not flag2) then
b:=b+a
end ;
writeln('number summ from 1 to 100 is: ',b) ;
end.
[/code]
• [code]
program program4;
{
probably the most elegant solution
}
var
a, b : integer ;
begin
b := 0 ;
for a := 1 to 100 do
if ((a mod 10) <> 7) and (((a div 10) mod 10) <> 7) then
b := b + a ;
writeln('number sum from 1 to 100 is: ', b) ;