Compilare: main.cpp: In function 'int main()': main.cpp:178:3: warning: this 'else' clause does not guard... [-Wmisleading-indentation] else ^~~~ main.cpp:180:5: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'else' fo.close(); ^~ main.cpp:164:9: warning: unused variable 'sol' [-Wunused-variable] int sol=-1; ^~~