foo.cpp: In function 'int mrge(int, int)':
foo.cpp:25:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
foo.cpp: In function 'int main()':
foo.cpp:36:7: error: 'T' was not declared in this scope
  cin>>T;
       ^
foo.cpp:34:10: warning: unused variable 'c' [-Wunused-variable]
  int a,b,c;
          ^