View Compilation Error

0_0_29525224_4147.cpp: In function 'int main()':
0_0_29525224_4147.cpp:31:5: error: 'cin' was not declared in this scope
     cin>>n;
     ^
0_0_29525224_4147.cpp:45:78: error: 'max' was not declared in this scope
                 f[i][j]=max(f[i][j-1]+val('-',s2[j]),f[i-1][j]+val(s1[i],'-'));
                                                                              ^
0_0_29525224_4147.cpp:45:78: note: suggested alternative:
In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/algorithm:62:0,
                 from 0_0_29525224_4147.cpp:2:
GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/stl_algo.h:3454:5: note:   'std::max'
     max(initializer_list<_Tp> __l, _Compare __comp)
     ^
0_0_29525224_4147.cpp:48:9: error: 'cout' was not declared in this scope
         cout<<f[n1][n2]<<endl;
         ^
0_0_29525224_4147.cpp:48:26: error: 'endl' was not declared in this scope
         cout<<f[n1][n2]<<endl;
                          ^