【C语言】求 a+aa+aaa+aaaa+aaaaa

#include<stdio.h>

int main()
{
int a = 0;
int Sn = 0;
printf("请输入a:");
scanf("%d", &a);
Sn = a + a * 11 + a * 111 + a * 1111 + a * 11111;
printf("%d+%d+%d+%d+%d=%d\n", a, a * 11, a * 111, a * 1111, a * 11111, Sn);
system("pause");

return 0;
}