111..1 SQUARED SPOJ

9952. 111..1 SQUARED 
CODE: GUANGGUN


#include<stdio.h>
#include<stdlib.h>
int main()
{
    long long int n,t,s,k;
while(scanf("%lld",&n)!=EOF)
{
if(n<10)
{
printf("%lld\n",n*n);
continue;
}
t=((n-10)/9)+1;
k=10+((t-1)*9);
s=((81*t)+1)+((n-k)*(n-k+2));
printf("%lld\n",s);
}
return 0;
}