View Compilation Error

0_0_36470132_2529.cpp: In function 'int main()':
0_0_36470132_2529.cpp:40:11: error: 'a' was not declared in this scope
  int mx = a[tot-1].first,num = a[tot-1].second;
           ^
0_0_36470132_2529.cpp:40:13: error: 'tot' was not declared in this scope
  int mx = a[tot-1].first,num = a[tot-1].second;
             ^
0_0_36470132_2529.cpp:48:8: error: 'num' was not declared in this scope
     if(num >= mx) printf("YES\n");
        ^