View Compilation Error

0_0_13540844_4309.cpp: In function 'int main()':
0_0_13540844_4309.cpp:3:27: error: 'a' was not declared in this scope
     while(~scanf("%d%d", &a, &b)) {
                           ^
0_0_13540844_4309.cpp:3:31: error: 'b' was not declared in this scope
     while(~scanf("%d%d", &a, &b)) {
                               ^