Can you name the twenty films (below) directed by Alfred Hitchcock in which he made a cameo appearance?

       
       
1.
2.
Strangers on a Train (1951)
Frenzy (1972)
3.
4.
Torn Curtain (1966)
Lifeboat (1944)
5.
6.
Psycho (1960)
Rear Window (1954)
7.
8.
North by Northwest (1959)
The Trouble with Harry (1955)
9.
10.
I Confess (1953)
To Catch a Thief (1955)
11.
12.
Vertigo (1958)
The Paradine Case (1947)
13.
14.
The Birds (1963)
The Wrong Man (1956)
15.
16.
Topaz (1969)
The Lady Vanishes (1938)
17.
18.
Dial M For Murder (1954)
Marnie (1964)
19.
20.
Foreign Correspondent (1940)
Rebecca (1940)