/in/foo.c: In function 'main':
/in/foo.c:17:13: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
 if(s[i]%4==0&&s[i]%100!=0||s[i]%400==0)
    ~~~~~~~~~^~~~~~~~~~~~~
/in/foo.c: In function 'tian':
/in/foo.c:46:11: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
 if((a%4==0&&a%100!=0||a%400==0)&&b>2)
     ~~~~~~^~~~~~~~~~
/in/foo.c:47:2: warning: 'm' may be used uninitialized in this function [-Wmaybe-uninitialized]
 m=m+1;
 ~^~~~