text: #include <stdio.h>
  #include <stdlib.h>
  
  int sum(int );
  
  int main()
  {
      int a,k;
      printf("Enter the Number upto which you want the sum of\n");
      scanf("%d",&a);
      k=sum(a);
      printf("The Sum of first %d numbers is %d",a,k);
  }
   int sum(int b)
   {
       int s;
       if(b==1)
          return b;
       s=b+sum(b-1);
       return s;
   }
  