foo.cc: In function 'int main()':
foo.cc:61:24: warning: variable 'd' set but not used [-Wunused-but-set-variable]
  int a,b,c,i,x,y,z,sum,d;
                        ^
foo.cc: In function 'int DaysOfMonth(int, int)':
foo.cc:57:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^

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