foo.cc: In function 'int main()':
foo.cc:9:12: error: expected primary-expression before '>=' token
    9 |  if(a<=90&&>=100)
      |            ^~
foo.cc:12:13: error: expected primary-expression before '>=' token
   12 |   if(a<=80&&>=89)
      |             ^~
foo.cc:15:14: error: expected primary-expression before '>=' token
   15 |    if(a<=70&&>=79)
      |              ^~
foo.cc:18:15: error: expected primary-expression before '>=' token
   18 |     if(a<=60&&>=69)
      |               ^~
foo.cc:21:15: error: expected primary-expression before '>=' token
   21 |      if(a<=0&&>=59)
      |               ^~

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