#include <iostream>
#include <fstream>
#include <string>

struct element
{ string symbol, name;
  int atno;
  double atwt; };

void print(element e)
{ cout << e.symbol << ", " << e.name << ", number = " << e.atno
       << ", atomic weight = " << e.atwt << "\n"; }

struct input
{ string line;
  int pos; };

input read_input()
{ input i;
  i.pos = 0;
  getline(cin, i.line);
  return i; }

char get_next(input & isys)
{ isys.pos += 1;
  return isys.line[isys.pos - 1]; }

void give_back(input & isys)
{ isys.pos -= 1; }

string read_symbol(input & in)
{ string s = "";
  char c = get_next(in);
  s += c;
  c = get_next(in);
  if (c>='a' && c<='z')
    s += c;
  else
    give_back(in);
  return s; }

int read_table(element array[])
              // don't type the &, it is there automatically for arrays
{ ifstream fi("atwt.txt");
  if (fi.fail())
  { cout << "Can't open the file\n";
    exit(1); }
  array[0].symbol = "Nx";
  array[0].name = "Nonexistium";
  array[0].atno = 0;
  array[0].atwt = 0;
  int n = 1;
  while (true)
  { string sym, name;
    double wt;
    fi >> sym >> name >> wt;
    if (fi.fail())
      break;
    array[n].symbol = sym;
    array[n].name = name;
    array[n].atno = n;
    array[n].atwt = wt;
    n += 1; }
  n -= 1;
  fi.close();
  return n; }

element find(string symb, element array[], int maxpos)
{ for (int i=1; i<=maxpos; i+=1)
    if (array[i].symbol == symb)
      return array[i];
  return array[0]; }

void main()
{ element table[110];
  int n = read_table(table);
  cout << n << " elements read\n";
  cout << "Enter molecular formulae:\n";
  input in = read_input();
  while (true)
  { string s = read_symbol(in);
    element e = find(s, table, n);
    if (e.atno == 0)
      cout << "no such element\n";
    else
      print(e); }
  cout << "Bye then.\n"; }