lamp.cpp: In function 'int main()':
lamp.cpp:40:9: warning: unused variable 'M' [-Wunused-variable]
40 | int M,ans=0,i;
| ^
lamp.cpp:40:11: warning: unused variable 'ans' [-Wunused-variable]
40 | int M,ans=0,i;
| ^~~
lamp.cpp:40:17: warning: unused variable 'i' [-Wunused-variable]
40 | int M,ans=0,i;
| ^
lamp.cpp:41:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
41 | scanf("%d",&N);
| ~~~~~^~~~~~~~~
lamp.cpp:42:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
42 | scanf("%s %s",a,b);
| ~~~~~^~~~~~~~~~~~~