C语言实现求S=a+aa+aaa+...+aa...a的值

#include <stdio.h>

int main() { int a,n; long int sn=0,tn=0; int count = 1;

printf('please input a and n\n');
scanf('%d,%d',&a,&n);
printf('a=%d, n=%d\n',a,n);

while(count <= n) {
    tn = tn + a;
    sn = sn + tn;
    a = a * 10;
    count++;
}

printf('a+aa+...=%ld\n',sn);
return 0;

}