How many books are in Isaac Asimov's Foundation series?
7
5
5
5
3
5
3
5
3
5
3
6
5
3
6
5
3
6
5
3
6
7
5
3
6
7
5
3
6
7
5
4
3
6
7
5
4
3
6
7
5
4
3
6
7
5
4
3
6
7
5
4
3
6
7
5
4
3
6
7
5
4
3
6
7
5
4
3
6
7
5
4
3
6
7
4
3
6
2
7
4
3
6
2
8
7
4
6
2
8
7
4
6
2
8
7
9
4
6
2
8
7
9
4
2
8
7
9
4
2
8
7
9
0
4
2
8
7
9
4
2
0
8
9
ten
4
2
8
0
109
9
4
2
10
ten
8
9
0
109
2
10
8
ten
9
2
0
10
109
8
108
9
ten
66
2
10
8
0
109
9
1
108
2
10
ten
66
8
9
1
0
109
2
108
10
8
ten
9
66
1
58
2
0
10
67
109
91
8
108
9
1
ten
66
57
2
10
58
62
8
0
67
109
91