UVA - 494 - Kindergarten Counting Game

#include <stdio.h>
#include <stdbool.h>

int main()
{
    char str[1500];
    while(gets(str)){
        bool flag=false;
        int i=0,counter=0;
            for(i=0;i<strlen(str);i++){
                if(flag){
                    if(!isalpha (str[i])){
                        flag=false;
                    }
                }
                if(isalpha (str[i]) &&!flag){
                    counter++;
                    flag=true;
                }
            }
        printf("%d\n",counter);
     }
    return 0;
}