count the number of patients who have been dead after having been diagnosed with gastroduodenal dis nec within 2 months since 2105.
select count( distinct t2.subject_id ) from ( select t1.subject_id, t1.charttime from ( select admissions.subject_id, diagnoses_icd.charttime from diagnoses_icd join admissions on diagnoses_icd.hadm_id = admissions.hadm_id where diagnoses_icd.icd9_code = ( select d_icd_diagnoses.icd9_code from d_icd_diagnoses where d_icd_diagnoses.short_title = 'gastroduodenal dis nec' ) ) as t1 group by t1.subject_id having min(t1.charttime) = t1.charttime and strftime('%y',t1.charttime) >= '2105' ) as t2 join ( select patients.subject_id, admissions.hadm_id, patients.dod from admissions join patients on patients.subject_id = admissions.subject_id where patients.dod is not null and strftime('%y',patients.dod) >= '2105' ) as t3 on t2.subject_id = t3.subject_id where ( datetime(t3.dod) between datetime(t2.charttime) and datetime(t2.charttime,'+2 month') ) or ( datetime(t2.charttime) between datetime(t3.dod) and datetime(t3.dod,'+2 month') )