input.txt
 1  date | value
 2  2011-01-03 | 3
 3  2011-01-03 | 2
 4  2011-01-03 | 1
 5  2011-01-03 | 1.2
 6  2011-01-09 | 1
 7  2012-01-11 | -1
 8  2001-42-42
 9  2012-01-11 | 1
10  2012-01-11 | 2147483648