Compilare: main.cpp: In function 'int main()': main.cpp:15:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation] for (i=2; i<=n; i++) ^~~ main.cpp:27:9: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for' fout<<-1; ^~~~