Pair the people#11288
There are people at a party. Each person can either join the dance as a single individual or as part of a pair with any other person. Find the number of different ways in which all people can join the dance.
One integer n~(1 \le n \le 10^5).
Print the number of different ways all people can join the dance. Print the answer modulo 10^9 + 7.
Let there be n = 3 people. They can dance in different ways: \{1, 2, 3\}, \{\{1, 2\}, 3\}, \{1, \{2, 3\}\}, \{\{1, 3\}, 2\}.
Example 1