Counting identifiers

Counting identifiers
Write the program that counts how many identifiers are in a given line. Identifier is a sequence of characters from set 'a'-'z' or 'A'-'Z' or '0'-'9' or '_', starting from any letter or underline character ('_').

Input
There are given some number of data sets. Each data set is a line consisting from the sequence of some number of words, separated by spaces and finishing with the end of line character (even the last one line). A word is a sequence of any ASCII character of code from 33 till 126 (see http://www.asciitable.com for more details), e.g., aqui28$-3q or _dat_. The second word is an identyfier, but the first one not.

Output
The number of identifiers in each line.

Example
Input:

Dato25 has 2 c-ats and 3 _dogs
op8ax _yu _yu67 great-job ax~no identifier.


Output:

4
3

//code
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
int main (){
    int i=0, n=0;
    char j;
    while((j=fgetc(stdin))!=EOF)
    {
        if(isalpha(j)>0 || j=='_')
                    i++;
        while((j=fgetc(stdin)))
        {
            if(isalpha(j)==0 && isdigit(j)==0 && j!='_'&& j!=' ' && j!='\n' && j!=EOF)
              n=1;

            }
            if(j==' '||j==EOF||j=='\n')
              break;
        } //somewhere here is mistake
              if(n>0)//here not sure
              {
                  i--;
                  n=0;
              }

              if(j==EOF||j=='\n')//this is right
              {
                  printf("%d\n",i);
                  i=0;
              }
              if(j==EOF)//this means nothing much
              {
                  break;
              }
      }
    return 0;
}