void putm(char* string, size_t m)
{
    while(*string && m--)
        putchar(*string++);
}

int main(void)
{

    char string[] = 
        

    int n = 3;
    int m = 4;
    char knownCharacter = '(';
    char knownSubstring[] = ;

    putm(string+n-1, m );                       putchar('\n');
    puts(string+n+1);                           putchar('\n');
    putm(string, strlen(string)-1);             putchar('\n');
    putm(strchr(string, knownCharacter), m );   putchar('\n');
    putm(strstr(string, knownSubstring), m );   putchar('\n');

    return EXIT_SUCCESS;
}