View Compilation Error

0_0_35639625_4139.cpp: In function 'int main()':
0_0_35639625_4139.cpp:11:2: error: 'cin' was not declared in this scope
  cin>>t;
  ^
0_0_35639625_4139.cpp:37:3: error: 'cout' was not declared in this scope
   cout<<m1[num[i]]<<endl;
   ^
0_0_35639625_4139.cpp:37:21: error: 'endl' was not declared in this scope
   cout<<m1[num[i]]<<endl;
                     ^