3. flow block

#while

x = 1
while x < 5:
    print(x)
    x += 1  

print("loop ended")

#continue while

x = 0
while x < 5:
    x += 1
    if x == 3:
        continue
    print(x)
    
#break while

x = 1
while x < 5:
    if x == 3:
        break
    print(x)
    x += 1
    
#else while

x = 1
while x < 5:
    print(x)
    x += 1
else:
    print('While loop is a great tool')
    
#nested while

x = 1
while x < 10:
    print(x)
    while x < 3:
        print("We are at the very beginning")
    x += 1
else:
    print('While loop is a great tool')