var f,g:text;  
    u,v,j,i,r,nr,n: longint;  
    a:array[1..100000]of longint;  
begin  
assign(f,'pairs.in');reset(f);  
assign(g,'pairs.out');rewrite(g);  
readln(f,n);  
for i:=1 to n do  
    readln(f,a[i]);  
    for i:=1 to n do  
    for j:=1 to n do  
        begin  
        if a[i]<>a[j] then begin  
             u:=a[i];  
             v:=a[j];  
             repeat  
             r:=u mod v;  
             u:=v;  
             v:=r;  
             until r=0;  
             if u=1 then nr:=nr+1;  
        end;  
        end;  
    writeln(g,nr div 2);  
    close(g);  
    end.