let i = require('fs').readFileSync('/dev/stdin', 'utf8').split('\n').slice(0, -1)
let a = Array.from(new Array(10)).map((e,i) => i)
for (let x=1; x<=i[0]; x++) {
  let l = i[x].split(' ')
  let f = l.pop()
  l = l.map((e) => e-0)
  if (f === 'NO') a = a.filter((e) => l.indexOf(e) === -1)
  else a = a.filter((e) => l.indexOf(e) !== -1)
}
console.log(a[0])