View Compilation Error

0_0_25004979_28847.cpp: In function 'int main()':
0_0_25004979_28847.cpp:46:7: error: 'flag' was not declared in this scope
       flag=1;
       ^
0_0_25004979_28847.cpp:53:16: error: 'flag' was not declared in this scope
     if(pos==0) flag=1;
                ^
0_0_25004979_28847.cpp:55:7: error: 'flag' was not declared in this scope
    if(flag) printf("No\n");
       ^