7 Replaced Int32 with int to shorten code length
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C# (5654 characters)

 Math.Log(Int32int.Parse(Console.ReadLine()),2)%1==0?"Y":"N"

C# (56 characters)

 Math.Log(Int32.Parse(Console.ReadLine()),2)%1==0?"Y":"N"

C# (54 characters)

 Math.Log(int.Parse(Console.ReadLine()),2)%1==0?"Y":"N"
6 Minor mistake
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C# (5856 characters)

 Math.Log(ToInt32Int32.Parse(Console.ReadLine()),2)%1==0?"Y":"N"

C# (58 characters)

 Math.Log(ToInt32.Parse(Console.ReadLine()),2)%1==0?"Y":"N"

C# (56 characters)

 Math.Log(Int32.Parse(Console.ReadLine()),2)%1==0?"Y":"N"
5 Reduced to 58 characters from 60
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C# (6058 characters)

 Math.Log(Convert.ToInt32.Parse(Console.ReadLine()),2)%1==0?"Y":"N"

C# (60 characters)

 Math.Log(Convert.ToInt32(Console.ReadLine()),2)%1==0?"Y":"N"

C# (58 characters)

 Math.Log(ToInt32.Parse(Console.ReadLine()),2)%1==0?"Y":"N"
4 Every answer has that label of the code length. It is important for viewers to see it for comparison with other versions.
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3 Replaced a variable by input stream.
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2 added 40 characters in body
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1
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