#include <bits/stdc++.h>

int main() {

  int x[3];
  int y[3];
  int m;
  int max;

  std::cin >> x[0] >> y[0];
  std::cin >> x[1] >> y[1];
  std::cin >> x[2] >> y[2];

  if( y[0] < y[1] ) {
    m = 1;
  }
  else {
    m = 0;
  }

  if( y[m] < y[2] ) {
    m = 2;
  }

  std::swap(x[0], x[m]);
  std::swap(y[0], y[m]);

  max = y[0] * y[1] * y[2];

  for(long i = x[0]; i < max; i += y[0]) {
    if( i % y[1] == x[1] and i % y[2] == x[2] ) {
      std::cout << i << std::endl;
      return 0;
    }
  }
  
  std::cout << -1 << std::endl;

  return 0;
  
}