View Compilation Error

0_0_27124549_17746.cpp: In function 'int main()':
0_0_27124549_17746.cpp:6:16: error: 'a' was not declared in this scope
 {scanf("%d%d",&a,&b);
                ^
0_0_27124549_17746.cpp:6:19: error: 'b' was not declared in this scope
 {scanf("%d%d",&a,&b);
                   ^
0_0_27124549_17746.cpp: At global scope:
0_0_27124549_17746.cpp:13:2: error: expected unqualified-id before 'return'
  return 0;
  ^
0_0_27124549_17746.cpp:16:1: error: expected declaration before '}' token
 } 
 ^