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Problems

Year of the Cow

Year of the Cow

Farmer John's cows are excited to learn that Chinese New Year was recently celebrated, ushering in the year of the Ox, always a bovine favorite.

As we know, the zodiac animals for Chinese calendar years follow a 12-year cycle: Ox, Tiger, Rabbit, Dragon, Snake, Horse, Goat, Monkey, Rooster, Dog, Pig, Rat, and then Ox again.

Bessie the cow is proud to say she was born in a year of the Ox, many years ago. Her friend Elsie wants to know how many years apart from Bessie she was born, and hopes you can help her deduce this by looking at relationships between the birth years of several cows on the farm.

Input

The first line contains an integer n (1n100). Each of the next n lines contains an 8-word phrase specifying the relationship between the birth years of two cows. It is of the form

"Mildred born in previous Dragon year from Bessie",

or

"Mildred born in next Dragon year from Bessie"

The last word is the name of a cow on the farm, which is either "Bessie" or a cow that has already been mentioned in a previous line of input.

The first word is the name of a cow on the farm who is not "Bessie" and who has not yet been mentioned in the input. All cow names have at most 10 characters that are in the range a..z or A..Z.

The 5-th word is one of the 12 zodiac animals above.

The 4-th word is either "previous" or "next". For example, if the phrase is "Mildred born in previous Dragon year from Bessie", then Mildred's year of birth was the Dragon year closest to and strictly before (not equal to) Bessie's birth year.

Output

Output the number of years by which Bessie and Elsie's birth years differ. It is guaranteed that this number can be determined by the input given.

Example

In the input above,

  • Elsie was born 12 years before Bessie.
  • Mildred was born 9 years before Bessie.
  • Gretta was born 17 years before Bessie.
  • Paulina was born 9 years after Bessie.
Time limit 1 second
Memory limit 128 MiB
Input example #1
4
Mildred born in previous Dragon year from Bessie
Gretta born in previous Monkey year from Mildred
Elsie born in next Ox year from Gretta
Paulina born in next Dog year from Bessie
Output example #1
12
Source 2021 USACO February, Bronze