C :

#include<stdio.h>
#include<string.h>
#define N 100
int fun(char *p);
int main()
{
	char f[100],*p = f;
	int n=0;
	gets(f);
	n=fun(f);
	printf("%d",n);
	return 0;
}

int fun(char *p)
{
	int n=0;
	while(*p!='\0')
	{
		if(*p==' ') n++;
		p++;
	}
	n=n+1;
	return n;
}

C++ :

#include<iostream>
using namespace std;
int main()
{
	int mm=0;
	string s;
	while(cin>>s)
	  {
	  	mm++;
	  }
	cout<<mm;
	return 0;
}