def fib(n):
    global F
    if n not in F:
        F[n] = fib(n-1)+fib(n-2)
    return F[n]

F = {0:1,1:1}
print(fib(int(input()))) def fib(n):
    global F
    if n not in F:
        F[n] = fib(n-1)+fib(n-2)
    return F[n] fib global F if n not in F:
        F[n] = fib(n-1)+fib(n-2)
     n not in F n F F[n] = fib(n-1)+fib(n-2) F[n] F n fib(n-1)+fib(n-2) fib(n-1) fib n-1 n 1 fib(n-2) fib n-2 n 2 return F[n] F[n] F n n n F = {0:1,1:1} F {0:1,1:1} 0 0 1 1 1 1 print(fib(int(input()))) print fib(int(input())) fib int(input()) int input() input F = {0:1,1:1} {0:1,1:1} F def fib(n):
    global F
    if n not in F:
        F[n] = fib(n-1)+fib(n-2)
    return F[n] def fib(n):
    global F
    if n not in F:
        F[n] = fib(n-1)+fib(n-2)
    return F[n] fib
def fib(n):
    global F
    if n not in F:
        F[n] = fib(n-1)+fib(n-2)
    return F[n]

F = {0:1,1:1}
print(fib(int(input())))
