let lines: string[] = [];
const reader = require('readline').createInterface({
  input: process.stdin,
  output: process.stdout
});

reader.on('line', function (line: string) {
  lines.push(line);
  if (lines.length === 2) {
    reader.close();
    main();
  }
});

function main () {
  const n = +lines[0];
  const nums = lines[1].split(' ').map((s,i) => [i+1, +s]).filter(e => e[1]);

  const res = result(n, nums);
  console.log(res);
}

function result (n: number, nums: number[][], res = 0): number {
  if (n === 0) return res;
  else {
    if (nums[nums.length-1][1] === 1) return result(n-1, nums.slice(0,nums.length-1), res * 10 + nums[nums.length-1][0]);
    else return result(n-1, [...nums.slice(0,nums.length-1), [nums[nums.length-1][0], nums[nums.length-1][1]-1]], res * 10 + nums[nums.length-1][0]);
  }
}