求Sn=a+aa+aaa+aaaa+aaaaa的前5项之和，其中a是一个数字.

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<stdlib.h>
int main(){
 int i, j;
 int sum = 0;
 scanf("%d", &i);
 int sum1=0;
 for (j = 1; j <= 5; j++)
 {
  sum1 = sum1 + i;
  sum = sum + sum1;
  i = i * 10;
  printf("%d =%d + %d\n", sum, sum, sum1);
 }
 printf("%d",sum);
 system("pause");
 return 0;
}