at t1 2MSS
at t2 4 MSS
at t3 8 MSS
at t4 16MSS (reach at threshold)
at t5 17MSS
at t6 18 MSS
at t7 19 MSS (time out occurs so threshold will be n/2 i.e. 19/2 )
it will start again with 1MSS
t8 1 MSS
t9 2 MSS
t10 4 MSS
t11 8 MSS
t12 9 MSS
t13 10 MSS
t14 11 MSS
so, at the end of 14 MSS will be 12MSS