import sys
import numpy as np



def main():
    n = int(input())
    P = np.fromstring(input(), np.int64, sep=' ') - 1
    ans = 0
    for i in range(n):
        if P[i] == i: continue
        j, = np.nonzero(P == i)
        P[i], P[j] = P[j], P[i]
        ans += 1
    print(ans)




if __name__ == '__main__':
    main()