Illumina S_sequence.txt is a fastq format?

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Illumina S_sequence.txt is a fastq format? Can I run soap directly using this S_sequence.txt? The file format is like this
@HWUSI-EAS523:1:1:0:1286#0/1
NGCTTACTGGTGCGACTTAGCTGGGATGTTTAGTGAACTGAAAATCCATG
+HWUSI-EAS523:1:1:0:1286#0/1
DLXZZZZZWQWWYXXZZZZWZZSWRTWZZZZZVXZZWZZXZVZXZZZZZZ

Another question is why I see N in this read, what the meaning of this N, should I get rid of it before I do the alignment by soap?

Thanks.

[ECO]

Please do some searches before asking this question.

Closing.