const input = require('fs')
  .readFileSync('/dev/stdin', 'utf8');
const [A, B, C, D] = input
  .split(/\s/)
  .map(v => +v);
for (i = 0; i <= A; i++)
  if (i * C > B || i * (C + 1) > D) break;
console.log(i - 1);