foo.c: In function 'main':
foo.c:7:9: error: 'survive' undeclared (first use in this function)
    7 |         survive[l+1]=0;
      |         ^~~~~~~
foo.c:7:9: note: each undeclared identifier is reported only once for each function it appears in
foo.c:15:13: error: expected '(' before 'survive'
   15 |          if survive[i]==0;
      |             ^~~~~~~
      |             (

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