http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=10022

finding_a_word.c

#include <stdio.h>
#include <string.h>

int main(void)
{
    char keyword[11];
    char word[32];
    int counter = 0;

    memset(keyword, '\0', sizeof(keyword));
    memset(word, '\0', sizeof(word));
    
    scanf("%s", keyword);
    getchar();

    while (scanf("%s", word), strcmp(word, "END_OF_TEXT"))
        if (!(strcasecmp(word, keyword))) counter++;

    printf("%d\n", counter);
    return 0;
}

SAMPLE

Input:
computer // <- keyword
Nurtures computer scientists and highly-skilled computer engineers
who will create and exploit "knowledge" for the new era.
Provides an outstanding computer environment.
END_OF_TEXT

Output:
3