#include <stdio.h>

int first_occurrence(char *string, char ch) {
    int position = -1;
    int index = 0;
    while (string[index] != '\0') {
        if (string[index] == ch) {
            position = index;
            break;
        }
        index++;
    }
    return position;
}

int main() {
    char input_string[] = "hello world";
    char character_to_find = 'o';
    printf("First occurrence of '%c' in '%s': %d\n", character_to_find, input_string, first_occurrence(input_string, character_to_find));
    return 0;
}