Masala C

Bilmasvoy algebra darsida uhlab qolibdi, shuning uchun u ustozi o'tib bergan darsni tinglamadi, darsning ohirida esa ustozi uyga vazifa berdi: yumaloq stolda n ta odam necha hil usulda o'tirishi mumkin. Bilmasvoyga ertangi darsda 2 olmasligi uchun yordam bering.

INPUT.TXT kirish faylining birinchi satrida bitta natural son $n (1≤n≤1000)$ beriladi

Masala javobini $10^9$ ga bo'lgandagi qoldiqni chop eting