const reader = require("readline").createInterface({
  input: process.stdin,
  output: process.stdout
});

let lines = [];

reader.on("line", line => lines.push(line));

reader.on("close", () => {
  const [a, b, c, d] = lines[0].split(' ').map(x => parseInt(x));
  console.log((a % d) * (b % d) % d * (c % d) % d);
});