View Compilation Error

0_0_33662090_24422.cpp: In function 'int main()':
0_0_33662090_24422.cpp:14:33: error: 'max' was not declared in this scope
             if(x==1) r=max(r,y+1);
                                 ^
0_0_33662090_24422.cpp:15:29: error: 'max' was not declared in this scope
             else l=max(l,y+2);
                             ^
0_0_33662090_24422.cpp:18:23: error: 'max' was not declared in this scope
         else r=max(l,r);
                       ^