View Compilation Error

0_0_37562302_11464.cpp: In function 'void solve()':
0_0_37562302_11464.cpp:7:2: error: 'string' was not declared in this scope
  string s1,s2,s3;
  ^
0_0_37562302_11464.cpp:8:2: error: 'cin' was not declared in this scope
  cin>>s1>>s2>>s3;
  ^
0_0_37562302_11464.cpp:8:7: error: 's1' was not declared in this scope
  cin>>s1>>s2>>s3;
       ^
0_0_37562302_11464.cpp:8:11: error: 's2' was not declared in this scope
  cin>>s1>>s2>>s3;
           ^
0_0_37562302_11464.cpp:8:15: error: 's3' was not declared in this scope
  cin>>s1>>s2>>s3;
               ^
0_0_37562302_11464.cpp:60:2: error: 'cout' was not declared in this scope
  cout << ans << endl;
  ^
0_0_37562302_11464.cpp:60:17: error: 'endl' was not declared in this scope
  cout << ans << endl;
                 ^
0_0_37562302_11464.cpp: In function 'int main()':
0_0_37562302_11464.cpp:65:8: error: 'cin' was not declared in this scope
  ll t; cin >> t;
        ^