View Compilation Error

0_0_35781135_11821.cpp: In function 'int main()':
0_0_35781135_11821.cpp:54:13: error: 'a' was not declared in this scope
   for(int i=a[1].a;i <= a[1].b;i++){ 
             ^
0_0_35781135_11821.cpp:57:9: error: 'a' was not declared in this scope
   int l=a[1].a,r=a[1].b;
         ^
0_0_35781135_11821.cpp:59:19: error: 'r' was not declared in this scope
    for(int j=l;j<=r;j++){
                   ^
0_0_35781135_11821.cpp:65:4: error: 'r' was not declared in this scope
    r+=a[i].b;
    ^