#include <stdio.h>       /* for printf in C programs */

int isletter(char c)
{   c &= 0xdf;    /* make uppercase */
    return 'A' <= c && c <= 'Z' ;
}

int countwords(char* str)  /* count words in a string */
{   int state = 1;          /* FSM state 1=no word, 2=word in progress */
    int count = 0;          /* count of words in string */
    char ch;                /* each character */
    while (ch = *str++)     /* go through string */
        switch (state)
        {
case 1:
            if (isletter(ch))   /* letter starts a word */
            {   count++;        /* count it */
                state = 2;      /* and change state */
            }
            break;
case 2:
            if (ch == ' ') {state = 1;}
        }
    return count;
}

int main (int argc, char* argv[])
{   int cnt;
    if (argc != 2)
    {   printf("Usage: countwds \'Some sentence here \'\n");
        return 1;
    }

    cnt = countwords(argv[1]);
    printf(" %d words\n", cnt);
    return 0;
}