/in/foo.cc: In function 'int find(int, int)':
/in/foo.cc:56:17: warning: unused variable 'ans' [-Wunused-variable]
     int las=0,w,ans=0;
                 ^~~
/in/foo.cc: In function 'int idx(char)':
/in/foo.cc:34:14: warning: 'v' is used uninitialized in this function [-Wuninitialized]
     if(v>='a'&&v<='z')
        ~~~~~~^~~~~~~~