n=input()

fn_first=1
fn_second=1

if n >= 2:
    for x in xrange(n-1):
        tmp = fn_first
        fn_first = fn_first + fn_second
        fn_second = tmp

print fn_first n=input() n input() input fn_first=1 fn_first 1 fn_second=1 fn_second 1 if n >= 2:
    for x in xrange(n-1):
        tmp = fn_first
        fn_first = fn_first + fn_second
        fn_second = tmp n >= 2 n 2 for x in xrange(n-1):
        tmp = fn_first
        fn_first = fn_first + fn_second
        fn_second = tmp x xrange(n-1) xrange n-1 n 1 tmp = fn_first tmp fn_first fn_first = fn_first + fn_second fn_first fn_first + fn_second fn_first fn_second fn_second = tmp fn_second tmp print fn_first = fn_first + fn_second fn_first + fn_second fn_first fn_second=1 1 fn_second n=input() input() n tmp = fn_first fn_first tmp fn_second = tmp tmp fn_second fn_first=1 1 fn_first
n=input()

fn_first=1
fn_second=1

if n >= 2:
    for x in xrange(n-1):
        tmp = fn_first
        fn_first = fn_first + fn_second
        fn_second = tmp

print fn_first