foo.cc: In function 'int main()':
foo.cc:5:8: warning: unused variable 'n' [-Wunused-variable]
    5 |  int m,n,c=0,i;
      |        ^
foo.cc:7:4: warning: 'm' is used uninitialized in this function [-Wuninitialized]
    7 |  r=double(m)/m;
      |    ^~~~~~~~~

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