pls check is your above found p is correct or wrong, or maybe i am doing calc wrong, advice
here is your selection P
115792089237316195423570985008687907853269984665640564039457584007908834672377
115792089237316195423570985008687907853269984665640564039457584007908834672281
115792089237316195423570985008687907853269984665640564039457584007908834672279
115792089237316195423570985008687907853269984665640564039457584007908834672153
115792089237316195423570985008687907853269984665640564039457584007908834671901
115792089237316195423570985008687907853269984665640564039457584007908834671691
115792089237316195423570985008687907853269984665640564039457584007908834671663
115792089237316195423570985008687907853269984665640564039457584007908834671591
115792089237316195423570985008687907853269984665640564039457584007908834671583
115792089237316195423570985008687907853269984665640564039457584007908834671301
115792089237316195423570985008687907853269984665640564039457584007908834671033
115792089237316195423570985008687907853269984665640564039457584007908834670671
go to this ecc calc and fill following details
http://www.christelbach.com/eccalculator.aspxp = 115792089237316195423570985008687907853269984665640564039457584007908834671583
a = 0
b = 7
px = 115301655840403608332148854465368444683257224081574702572138639602380667382125
py = 103799472776126890762485670055583971987299536955028941653349419016168013365384
qx = 52658829913452240860711750781961153521895864895692055913373819304893658879667
qy = 33725064078989563529395744584539757872089003472888698368252453876478056770565
and press P + Q
you will see B=7 changed to
b = 32267065813313537246304986561842436172856576584501774751507060994620472625355
mean your Prime value for fit in formula Y2=X3+AX+B , p prime Failed
save try all with P value to change, only p value original got by 977 will work, and b =7 will never change on that testing site
can you all start again to find correct P other then - 977, which stand for b =7
or advice me where i am wrong
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Question is below is simple formula for use P to substract 2 point, there is no n value involve,
p4 = int(2**256 - 2**32 - 977)
dx = (x1 - x2) % p4
dy = (y1 - ((p)-y2)) % p4
c1 = (dy * gmpy2.invert(dx, p4)) % p4
cu = dy * gmpy2.invert(dx, p4) % p4
Rx = (((c1*c1)%p4) - x2 - x1) % p4
Ry = ((c1*((x2 - Rx))) - y3) % p4
print (Rx , Ry) # 6 sub, 3 mul, 1 inv
print (hex(Rx), hex(Ry))
if P we choose from your generated P list as above you mention, results goes wrong, and even its fail to comply with B = 7