/in/foo.cc: In function 'int main()':
/in/foo.cc:21:3: warning: 'l' may be used uninitialized in this function [-Wmaybe-uninitialized]
   if(l==0){
   ^
/in/foo.cc:24:18: warning: 'k' may be used uninitialized in this function [-Wmaybe-uninitialized]
   if((!strcmp(a[k+1],s1))||(!strcmp(a[l-1],s1))){
                  ^