#include<stdio.h>
void C_program018()//求2+22+222+2222+22222.......等的和；
{
	int num,bit,i=0;
	long sum=0,mutil=0;
	printf("enter two number :\n");
	scanf("%d,%d",&num,&bit);
	printf("num=%d,bit=%d\n",num,bit);
	while(i<bit)//求出最后一個數mutil和最后的總和sum
	{
		mutil=mutil+num;
		sum=sum+mutil;
		num=num*10;

		i++;
	}

	printf("mutil=%d,sum=%d\n",mutil,sum);

}