There is a graph with n nodes.The edges are generated with different probabilities.

P[i][j] is the probability of generating the edge i->j .

For every i, you want to know the probability that the first node can go to the i-th node through the generated edges .

n<=80

I don't know how to solve it ,can you help me?

if integers A and B satisfy gcd(A,B)=1,why there are always two integers x and y that x*A-y*B=1?