/*打表把素数能组合的数先设置成相应的位数*/
/* if n equals two and n is No.1 position of prime factors so four position of prime factors is no.1,as well*/
/* although two can combined six but three also can combined six */
/* and three position of prime factors is two ,two covered one then six largest prime factor */
/*position is two now, have fun ;-) */
#include <stdio.h>
#include <stdlib.h>
#define MAX 1000000
/* run this program using the console pauser or add your own getch, system("pause") or input loop */
int main(int argc, char *argv[]) {
int *lpf = malloc( MAX*sizeof(int) ); /*if use "int lpf[MAX]" could be overflow*/
int n , num ;
int i , j ;
num = 0 ;
lpf[1] = 0 ;
for( i = 2 ; i < MAX ; i++ ) {
if( 0 == lpf[i] ){
num++ ;
for( j = i ; j < MAX ; j=j+i )
lpf[j] = num ;
}
}
while( scanf("%d",&n) != EOF )
printf("%d
",lpf[n]);
return 0;
}