/in/foo.cc: In function 'int main()':
/in/foo.cc:6:11: warning: unused variable 'a' [-Wunused-variable]
     int k,a=0,b=1,m=0;  
           ^
/in/foo.cc:6:15: warning: unused variable 'b' [-Wunused-variable]
     int k,a=0,b=1,m=0;  
               ^
/in/foo.cc:6:19: warning: unused variable 'm' [-Wunused-variable]
     int k,a=0,b=1,m=0;  
                   ^