#include <stdlib.h>
#include <stdio.h>

int SumTo(int n);

int main(void) {
  int  n;
  printf("The integer n, please: ");
  scanf("%d",&n);
  printf("sum = %d\n", SumTo(n));
  return EXIT_SUCCESS;
}

int SumTo (int n) {      /* computes 1 + 2+ ... + n */
  int i, sum;            /* Local variables for SumTo */
  sum = 0;               /* initialize sum to 0 */
  for (i = 1;  i <= n;  ++i) {   
    sum = sum + i;                
  }
  return sum;            /* Return the VALUE of sum */
}