View Compilation Error

0_0_22816199_28662.cpp: In function 'int main()':
0_0_22816199_28662.cpp:14:5: error: 'cin' was not declared in this scope
     cin>>t;
     ^
0_0_22816199_28662.cpp:30:9: error: 'cout' was not declared in this scope
         cout<<N[i-k+1]<<endl;
         ^
0_0_22816199_28662.cpp:30:25: error: 'endl' was not declared in this scope
         cout<<N[i-k+1]<<endl;
                         ^