def fib(n):
    if ft[n] != 0:
        return ft[n]
    else:
        ft[n] = fib(n - 1) + fib(n - 2)
        return ft[n]

ft = [0] * 45
ft[0] = ft[1] = 1
print fib(int(input())) def fib(n):
    if ft[n] != 0:
        return ft[n]
    else:
        ft[n] = fib(n - 1) + fib(n - 2)
        return ft[n] fib if ft[n] != 0:
        return ft[n]
    else:
        ft[n] = fib(n - 1) + fib(n - 2)
        return ft[n] ft[n] != 0 ft[n] ft n 0 return ft[n] ft[n] ft n ft[n] = fib(n - 1) + fib(n - 2) ft[n] ft n fib(n - 1) + fib(n - 2) fib(n - 1) fib n - 1 n 1 fib(n - 2) fib n - 2 n 2 return ft[n] ft[n] ft n n n ft = [0] * 45 ft [0] * 45 [0] 0 45 ft[0] = ft[1] = 1 ft[0] ft 0 1 = ft[1] = 1 ft[1] ft 1 1 print fib(int(input())) fib int(input()) int input() input def fib(n):
    if ft[n] != 0:
        return ft[n]
    else:
        ft[n] = fib(n - 1) + fib(n - 2)
        return ft[n] def fib(n):
    if ft[n] != 0:
        return ft[n]
    else:
        ft[n] = fib(n - 1) + fib(n - 2)
        return ft[n] fib ft = [0] * 45 [0] * 45 ft
def fib(n):
    if ft[n] != 0:
        return ft[n]
    else:
        ft[n] = fib(n - 1) + fib(n - 2)
        return ft[n]

ft = [0] * 45
ft[0] = ft[1] = 1
print fib(int(input()))