#include <stdio.h>
int main(void)
{
	long n;
	long k = 1;
	printf("\n请输入该数：");
	scanf("%ld",&n);
	do{
		k *= n % 10;
		n /= 10;
	} while(n);
	printf("%ld\n",k);
	return 0;
}

#include <stdio.h>
int main(void)
{
	int m = 0, mc = 0, k;
	scanf("%d", &k);
	while((k >= 13) && (mc < 10)) {
		if( (k%13 == 0) || (k%17 == 0)){
			m = m + k;
			mc++;
		}
		k--;
	}
	printf("\n%5d\n",m);
	return 0;
}

#include <stdio.h>
int main(void)
{
	int n, i;
	printf("\n请输入一个数：\n");
	scanf("%d", &n);
	printf("%d = ", n);
	for( i = 2; i <= n; i++ ) {
		while(n - i) {
			if( !(n % i) ) {
				printf("%d", i);
			   	n = n / i;
				   if(n != 0) {
				   	printf(" * ");
				   }		
			}
			else{
				break;
			}	
		}
		
	}
	printf("%d", n);
	return 0;
}