write a program in c to display as follows:

enter 1st number =1
enter last number=10

sum is 1+2+3+4+5+6+7+8+9+10 = 55.

note:
i did the program as follows:

#include<stdio.h>
#include<conio.h>
void main()
{
int a=1;
int c=0;
clrscr();
while(a<=10)
{
c=c+a;
a++;
}
printf("\n the sum= ",c);
getch();
}

output is:
sum=55.
but i actually want as
sum is 1+2+3+4+5+6+7+8+9+10 = 55.

can anybody help me?
thank you.