Cod sursa(job #160873)
Utilizator | Data | 17 martie 2008 10:34:52 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | fpc | Status | done |
Runda | Arhiva educationala | Marime | 0.45 kb |
program ciur;
var f,g:text;
i,j,n,k,s:longint;
a:array[1..2000000]of byte;
begin
assign(f,'ciur.in');reset(f);
assign(g,'ciur.out');rewrite(g);
readln(f,n);
s:=0;
for i:=2 to n do
if a[i]=0 then begin
k:=i;
s:=s+1;
for j:=2 to n div k do a[j*k]:=1;
end;
writeln(g,s);
close(f);
close(g);
end.