foo.c: In function 'main':
foo.c:7:9: error: variable-sized object may not be initialized
    7 |         int survive[L+1]={0};
      |         ^~~
foo.c:5:25: warning: unused variable 'i' [-Wunused-variable]
    5 |         int L,m,num,a,b,i;
      |                         ^

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