#python 2.7.12

N = int(input());
i = N-1;

while (i >= 2):
    
    flag = True;
    j = 2;
    
    while (flag) and (j < i):
        
        if not(i % j): flag = False; break;
        j+=1;
        
    if (flag): print(i)
    i-=1;