How many books are in Isaac Asimov's Foundation series?
7
3
3
3
3
3
3
5
4
2
3
5
4
2
3
5
4
2
3
5
4
2
3
5
4
2
3
5
4
2
3
5
1
4
2
3
5
1
4
2
3
5
1
4
7
2
3
5
1
4
6
7
2
3
5
1
4
6
7
2
3
5
1
4
6
0
7
2
3
5
1
4
6
7
2
3
5
1
4
6
7
2
3
5
1
4
6
7
2
5
1
4
8
6
7
2
5
1
4
8
6
7
2
5
1
4
8
6
7
2
5
1
4
8
6
7
2
5
1
4
8
9
6
7
2
1
8
9
6
7
1
8
9
6
7
1
11
8
9
6
10
7
1
11
8
9
6
10
7
13
1
11
8
9
12
6
10
7
13
1
11
8
9
12
6
10
7
13
11
8
9
12
6
10
7
13
11
8
9
12
6
10
7
13
11
8
9
12
6
10
13
11
8
9
66
102
132
116
123
62
144