How many entries are there in the Left 4 Dead series?
2
3
3
5
4
3
5
4
3
2
5
4
3
2
5
4
3
2
5
4
3
2
5
4
3
2
5
4
3
1
2
5
4
3
1
2
6
5
4
3
1
2
6
5
7
4
3
1
2
6
5
7
0
4
3
1
2
6
5
7
4
3
1
0
2
6
5
7
4
3
8
1
2
0
6
5
7
4
3
8
1
9
2
6
5
7
0
4
3
8
1
9
2
6
5
7
4
3
8
1
9
2
6
5
7
4
3
8
1
9
2
6
5
7
4
3
8
1
13
9
2
6
5
7
10
4
8
1
13
9
2
6
5
7
10
4
8
1
13
9
2
6
7
10
8
1
13
9
2
6
7
10
8
1
13
9
6
7
10
8
1
13
9
6
7
14
10
8
1
13
9
6
7
14
10
8
1
13
9
ten
6
7
14
10
8
11
1
13
9
6
7
ten
14
10
8
11
13
9
6
ten
ten