49
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It does not matter what you put after this. This will not be read.

the song is 12.328 seconds long.
12.328 ~ 12.25
12.328 is close to 12.25 seconds (or 48 + 1 quater seconds)

Figure out how many quarter seconds are there in 12.25 seconds
12 * 4 = 48
0.25/0.25 = 1;

48 + 1 = 49

Once you figure out how many quarter seconds there are in your song you put that number as the first line. 
Note: it can not have any decimal points.