a= prima zi
b= a.doua zi
c = a treia zi
a+b+c=956
a+b=565
b+c=495
565+c=956 /-
c=391 ( a 3 a zi )
b+391=495 /-
b= 104 ( a 2 a zi )
a+104=565 /-
a=461 ( prima zi )
sau :
956-565=391 paini ( a 3 a zi )
495-391=104 paini ( a 2 a zi )
565-104=461 paini ( prima zi )