WAP to Find Next Greater Palindrom Then the Given Number

#include

int ten(int s)
{
int i=1,product=1;
for(i=1;i<=s;i++)
product=product*10;
return product;
}
int main()
{
int n=0,num=0,b=0,c=0,d=0,i=1,input=99999,upper=0,lower=0,output=0;

num=input;
while(num!=0)
{
n++;
num/=10;
}
num=input;
printf("\n n=%d",n);
lower=num%ten(n/2);
printf("\nlower=%d",lower); //34 45
c=num/ten(n/2); //12 123
d=c;
if(n%2!=0)//if not even digits
d=c/10; // 12 12
printf("\n%d%d",c,d);
while(d!=0)
{
upper=upper*10+(d%10);
d=d/10;
}
printf("\nupper=%d",upper);//21 21
if(upper>lower)
{
output=c*ten(n/2)+upper;
}
else
{
c=c+1; //124
d=c;
upper=0;
if(n%2!=0)
d=d/10; //12
while(d!=0)
{
upper=upper*10+(d%10);
printf("\nd=%d",d);
d=d/10;
}
output=c*ten(n/2)+upper;
}
printf("\noutput=%d",output); //1331 12421

}