letter counter

letter counter

#include<stdio.h>
int main()
{
      char str[100];
      int i=0,nl=0;
      gets(str); // it takes input with space

      while(str[i] !='\0') // null termination character, it marks the the end of string
      {
           char ch= str[i];
              if (ch>= 'A' && ch<= 'Z' || ch>= 'a' && ch<= 'z')
              nl++;
                i++;
      }
            printf("Letter : %d\n",nl);
            return 0;

}