foo.cpp: In function 'int main()':
foo.cpp:16:21: error: 'scanf' was not declared in this scope
 scanf("%d%d", &n, &m);
                     ^
foo.cpp:23:8: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 if(pos > g.size()) pos = k + 1;
        ^
foo.cpp:27:19: error: 'printf' was not declared in this scope
 printf("%d\n", ans);
                   ^