/in/foo.cc: In function 'int main()':
/in/foo.cc:29:2: warning: 'sum2' may be used uninitialized in this function [-Wmaybe-uninitialized]
  if(min>sum2) min=sum2;
  ^~
/in/foo.cc:5:31: warning: 'sum1' may be used uninitialized in this function [-Wmaybe-uninitialized]
     int n,a1,a2,b1,b2,c1,c2,m,sum1,sum2,sum3;
                               ^~~~
/in/foo.cc:5:41: warning: 'sum3' may be used uninitialized in this function [-Wmaybe-uninitialized]
     int n,a1,a2,b1,b2,c1,c2,m,sum1,sum2,sum3;
                                         ^~~~