# HackerRank Set .union() Operation solution in python

In this Set .union() operation problem we need to develop a python program that can read four lines of input and then we need to print the total number of students who have at least one subscription on the output screen.

## Problem solution in Python 2 programming.

```eng = set()
fre = set()
n = raw_input()
for i in raw_input().split(' '):
m = raw_input()
for i in raw_input().split(' '):
sol = eng.union(fre)
print len(sol)```

## Problem solution in Python 3 programming.

```# Enter your code here. Read input from STDIN. Print output to STDOUT
n = int(input())
l = list(input().split())
m = int(input())
k = list(input().split())

s1 = set(l)
s2 = set(k)

print(len(s1.union(s2)))```

### Problem solution in pypy programming.

```# Enter your code here. Read input from STDIN. Print output to STDOUT
n = input()
s = set(map(int, raw_input().split()))

m = input()
t = set(map(int, raw_input().split()))

print len(s.union(t))```

### Problem solution in pypy3 programming.

```n = int(input())
A = set(map(int, input().split()))
m = int(input())
B = set(map(int, input().split()))

ans = A.union(B)
print(len(ans))```