#include <stdio.h>

int main(void)
{
    int count = 0; // // counter for counting
    int letter, ok = 0; // ok is a indicator var

    printf("Write the text.\n");

    while( (letter = getchar()) != EOF ) // whilte untill EOF - CTRLZ .
    {
        switch(letter)
        {
            case 'y': case 'Y': // Checks the letter for y or Y with capslock
                ok = 1;
            continue;

            case 'e': case 'E': // Checks the letter for e or E with capslock
                if(ok++ == 1) continue;
            break;

            case 's': case 'S': // Checks the letter for s or S with capslock
                if(ok == 2) ++count;
            break;
        }

        ok = 0;
    }

    printf("The word yes has appeared %d times in the text.\n", count);

    return 0;
}