foo.c: In function 'main':
foo.c:9:18: warning: left-hand operand of comma expression has no effect [-Wunused-value]
    9 |         for(sn<=k,n++)
      |                  ^
foo.c:9:22: error: expected ';' before ')' token
    9 |         for(sn<=k,n++)
      |                      ^
      |                      ;
foo.c:9:22: error: expected expression before ')' token

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