How many United States presidents did not have any biological children?
5
2
2
2
3
2
1
3
2
1
3
2
1
3
4
2
1
3
4
2
1
3
4
2
1
3
4
2
1
3
5
4
2
1
3
5
4
2
1
3
5
4
2
1
3
5
4
2
1
3
5
4
2
1
3
5
4
0
2
1
3
5
4
7
2
1
3
5
4
0
7
2
1
3
5
4
0
7
2
1
3
5
4
7
0
2
1
3
5
4
6
7
1
3
5
4
0
6
7
1
3
5
4
0
6
7
1
5
4
8
6
7
0
5
4
8
6
7
5
9
4
0
8
6
7
5
9
8
6
7
5
9
8
6
7
5
9
8
13
6
7
5
9
8
13
6
7
9
11
8
13
6
7
9
11
8
13
6
7
9
11
8
13
6
7
9
11
8
13
6
7
10
9
11
8
13
6
7
10
9
11
8
13
6
7
10
9
11
8
13
6
10
9
11
8
13
6
No
12
10
No