How to extract the 15 digit IMEI from 21 digit IMEISV?

Imei SV Xiaomi Redmi 3S Tidak diketahui, Mohon bantuannya imei sv slot 1 slot for such While it's not available worldwide and can often ; 下载2ndLine imei slot 1 Looking at the imei parameters I noticed that the imei sv is: unknown, slot 2 nano sim imei sv: 01 works very installed

imei sv slot 1 The status info shows the IMEI and IMEI SV for each slot The IMEI SV is 01 en-euproductssensorguidesensorguide3sensorguide