A string of numbers is arranged according to the following rule, so what is the 50th number? 1 2 3 2 3 4 3 4 5 4 5 6

A string of numbers is arranged according to the following rule, so what is the 50th number? 1 2 3 2 3 4 3 4 5 4 5 6

Change the arrangement:
one hundred and twenty-three
two hundred and thirty-four
three hundred and forty-five
four hundred and fifty-six
……
What's the number 50?
The first number of each row is arranged in order, that is, the third row, and each row is three consecutive natural numbers
50÷3=16…… two
The number 50 is in line 16 + 1 = 17. The second number in line 17 is 18, so the number 50 is 18