View Compilation Error

0_0_14202046_30723.cpp: In function 'void pushup(int)':
0_0_14202046_30723.cpp:31:56: error: 'max' was not declared in this scope
     tree[node].lm=max(tree[node*2].lm,tree[node*2+1].lm);
                                                        ^
0_0_14202046_30723.cpp: In function 'int main()':
0_0_14202046_30723.cpp:95:43: error: 'max' was not declared in this scope
             if(x<=0)  ans=max(ans,sum[i]/p);
                                           ^
0_0_14202046_30723.cpp:98:43: error: 'max' was not declared in this scope
                 ans=max(ans,query(1,n,1,x));
                                           ^