var input = require("fs").readFileSync("input.txt").toString().replace(/\n/g, "").replace(/\r/g, ""); var parts = []; while(input.length > 0){ if(input[0] == "("){ var len = input.match(/(\(([0-9]+)x([0-9]+)\)).*/); parts.push(input.slice(0, len[1].length + parseInt(len[2]))); input = input.slice(len[1].length + parseInt(len[2])); } else{ parts.push(input[0]); input = input.slice(1); } } parts = parts.map(function(part){ if(part[0] == "("){ var len = part.match(/(\(([0-9]+)x([0-9]+)\))(.*)/); return parseInt(len[2]) * parseInt(len[3]); } else{ return part.length } }); console.log(parts.reduce((a, b)=>(a + b)));