text: #!/usr/bin/env node
  
  const fs = require('fs');
  
  const code = fs.readFileSync('index.js', 'utf-8');
  
  const repls = {};
  
  let i = 1;
  
  const newCode = code.replace(/_?op\d+/g, m => {
      if (!repls.hasOwnProperty(m)) {
          repls[m] = i;
          i++;
      }
      return `op${repls[m]}`;
  });
  
  console.log(newCode);
  