/in/foo.cc: In function 'int main()':
/in/foo.cc:11:13: error: 'i' was not declared in this scope
   if(number[i]=='7')
             ^
/in/foo.cc:13:5: error: 'sum' was not declared in this scope
     sum=two[cnt];
     ^~~
/in/foo.cc:13:13: error: 'cnt' was not declared in this scope
     sum=two[cnt];
             ^~~
/in/foo.cc:16:3: error: 'cnt' was not declared in this scope
   cnt+=1;
   ^~~
/in/foo.cc:19:25: warning: format '%d' expects argument of type 'int', but argument 2 has type 'long long int' [-Wformat=]
   printf("%I64d\n",ans-1);
                         ^