const fs = require('fs');
fs.readFile('input.file', 'utf8', (err, data) => {
  const lines = data.split('\n');
  let index = 0;
  const initializationExpression = new RegExp(/(?:Var|,)\s*([a-zA-Z]\w*\s*=\s*[\d\?])/g);
  const operationExpression = new RegExp(/[a-zA-Z].*?=\s*[a-zA-Z].*?\+\s*[a-zA-Z]\w*/);
  const outputExpression = new RegExp(/^Output\s([a-zA-Z]*)/);

  const matches = {
    initializations: [],
    operations: [],
    outputs: [],
  }
  for (let line of lines){
    let match = null;
    while((match = initializationExpression.exec(line)) !== null) {
      matches.initializations.push(match[1]);
    }
    if (operationExpression.test(line)) {
      matches.operations.push(line);
    }
    let output = null;
    if ((output = outputExpression.exec(line)) !== null) {
      matches.outputs.push(output[1]);
    }
  }
  let op = '(function () {\n';
  matches.initializations.forEach(initialization => {
    op = `${op.length ? op + '\tlet ' + initialization + ';\n' : 'let ' + initialization + ';\n'}`;
  });
  matches.operations.forEach(operation => {
    op = `${op}\n\t${operation};`;
  });
  op = `${op}\n\n\treturn ${matches.outputs[0]};\n})()`;
  fs.writeFileSync('output.file', op);

  console.log(eval(op));
});