How to prove equality of this geometry triangle question, thanks.

[novodexx]

Junior high school 9th grade final exam, ?ABC， AM=AN, MP=NQ, PB=QC, prove: AB=AC


I tried connect M to N, and draw from A to middle point of MN, then translate and/or rotage ?NCQ to flip it. but no luck, now feel very frustrated. appreciated for your any help.