So iam able with your help to store the 21 characters in an array in the Local Node (First Arduino)

what i have to do next i cant quite put it in code

i have 21 characters 9 out of this will represent my student number the remaining 12 will be as follows

1,x1,x2,2,x3,x4,3,x5,x6 and 4,x7,x8

1,2,3 an 4 are the IDS For nodes RN1,RN2, RN3 and RN4

x1,x2,x3,x4,x5,x6,x7 and x8, are any numbers between 0, 9

For RN1 = X1+X2 =?

RN2 = X3+X4 =?

RN3 = X5+X6 =? and lastly

RN4 = X7+X8 =?

so the addition of these if the answer is least out of all these calculations

the LN will send the first 9 bytes to this node

so we want to only trasnmit throught RN3 but if RN1 gets the least then we dont trasmit anything other than the name of the node but if RN3 is the least then we transmit the first 9 bytes add each individidually so if the first 9 bytes is 213141312 then once weve sent the data to rn3, rn3 will add 2+1+3+1+4+1+3+1+2 = get the answer and transmit it back to LN (first arduino) and this result will be displayed in the serial monitor

no i understand the logic i just cant put it into code for example how do i differentiate between nodes and do the calculations for each to find out which node is the least cost ?