Compilare: user.cpp: In function ‘int main()’: user.cpp:12:12: warning: suggest parentheses around comparison in operand of ‘&’ [-Wparentheses] while(a>='a'&a<='z'||a>='A'&&a<='Z'){ ^ user.cpp:12:32: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] while(a>='a'&a<='z'||a>='A'&&a<='Z'){ ^ user.cpp:19:16: warning: suggest parentheses around comparison in operand of ‘&’ [-Wparentheses] while(a>='a'&a<='z'||a>='A'&&a<='Z'){ ^ user.cpp:19:36: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] while(a>='a'&a<='z'||a>='A'&&a<='Z'){ ^