How many presidents were never married?
1
2
2
4
3
2
4
3
2
4
3
2
4
3
2
4
3
5
2
4
1
3
5
2
4
1
3
5
2
4
1
3
5
2
4
1
3
5
2
4
1
3
5
2
7
4
1
3
5
2
7
4
1
3
5
2
7
4
1
3
5
2
7
0
4
1
3
5
2
7
4
1
3
0
5
2
7
8
4
1
3
5
2
6
0
7
8
4
1
3
5
2
6
7
8
4
1
3
5
2
6
7
8
4
1
3
5
6
9
7
8
4
1
3
5
6
9
7
8
1
5
6
9
7
8
13
1
5
6
9
7
8
13
1
5
6
9
7
8
13
1
5
6
9
11
7
8
13
1
6
9
11
7
8
13
6
9
11
7
8
13
10
6
9
11
7
8
13
10
6
9
11
7
8
13
10
6
9
11
7
8
12
13
10
6
9
11
8
12
13
10
6
9
11
8
12
13
10
6
9
213