View Compilation Error

100054_0_31476.cpp: In function `int main()':
100054_0_31476.cpp:5: error: redeclaration of `int x1'
100054_0_31476.cpp:5: error: `int x1' previously declared here
100054_0_31476.cpp:5: error: redeclaration of `int y2'
100054_0_31476.cpp:5: error: `int y2' previously declared here
100054_0_31476.cpp:6: error: `x2' undeclared (first use this function)
100054_0_31476.cpp:6: error: (Each undeclared identifier is reported only once for each function it appears in.)
100054_0_31476.cpp:6: error: `y1' undeclared (first use this function)