//Number of steps in Hackerearth
// Sample code to perform I/O:

process.stdin.resume();
process.stdin.setEncoding("utf-8");
var stdin_input = "";

process.stdin.on("data", function (input) {
    stdin_input += input;                               // Reading input from STDIN
});

process.stdin.on("end", function () {
   main(stdin_input);
});

function main(input) {

    var data = input.split('\n');
    var num = parseInt(data[0],10); 

    var aa = data[1].split(' ').map(function(item) { return parseInt(item, 10);});

var bb = data[2].split(' ').map(function(item) { return parseInt(item, 10);});

   process.stdout.write(f(aa,bb));
   //console.log(f(aa,bb));
   
   // Writing output to STDOUT
 
}

// Warning: Printing unwanted or ill-formatted data to output will cause the test cases to fail



// Write your code here
// Sample code to perform I/O:
//Enter your code here

function f(A, B){
  const n = A.length;
  const m = Math.min(...A);
  let result;
  
  for (let t=m; t>=0; t--){
    result = 0;
    
    for (let i=0; i<n; i++){
      if ((A[i] - t) % B[i] == 0){
        result = result + (A[i] - t) / B[i];
        
      } else {
        result = -1;
        break;
      }
    }
    
    if (result > -1)
      return result.toString();
  }
  
  return result.toString();
}