View Compilation Error

0_0_18505970_23652.cpp: In function 'int main()':
0_0_18505970_23652.cpp:6:54: error: redeclaration of 'long long int z'
  long long i,j,n,m,a[10001],p2=0,p1=0,z,t,o,b[10001],z;
                                                      ^
0_0_18505970_23652.cpp:6:39: note: 'long long int z' previously declared here
  long long i,j,n,m,a[10001],p2=0,p1=0,z,t,o,b[10001],z;
                                       ^