public static void main ( String [ ] args ) throws IOException {
  BufferedReader br = new BufferedReader ( new InputStreamReader ( System . in ) ) ;
  int n = Integer . parseInt ( br . readLine ( ) ) ;
  long t_pre = 1 , a_pre = 1 ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    String [ ] str = br . readLine ( ) . split ( " " ) ;
    long t = Integer . parseInt ( str [ 0 ] ) ;
    long a = Integer . parseInt ( str [ 1 ] ) ;
    long rate = Math . max ( t_pre / t + ( t_pre % t == 0 ? 0 : 1 ) , a_pre / a + ( a_pre % a == 0 ? 0 : 1 ) ) ;
    t_pre = rate * t ;
    a_pre = rate * a ;
  }
  System . out . println ( t_pre + a_pre ) ;
}

public static void main ( String [ ] args ) throws IOException { BufferedReader br = new BufferedReader ( new InputStreamReader ( System . in ) ) ; int n = Integer . parseInt ( br . readLine ( ) ) ; long t_pre = 1 , a_pre = 1 ; for ( int i = 0 ; i < n ; i ++ ) { String [ ] str = br . readLine ( ) . split ( " ▁ " ) ; long t = Integer . parseInt ( str [ 0 ] ) ; long a = Integer . parseInt ( str [ 1 ] ) ; long rate = Math . max ( t_pre / t + ( t_pre % t == 0 ? 0 : 1 ) , a_pre / a + ( a_pre % a == 0 ? 0 : 1 ) ) ; t_pre = rate * t ; a_pre = rate * a ; } System . out . println ( t_pre + a_pre ) ; }
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