foo.cc: In function 'int main()':
foo.cc:14:22: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
         if(a==11&&a>b&&a-b>=2||b==11&&b>a&&b-a>=2){
            ~~~~~~~~~~^~~~~~~~
foo.cc:19:27: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
         else if(a>=11&&a>b&&a-b>=2||b>=11&&b>a&&b-a>=2){
                 ~~~~~~~~~~^~~~~~~~
foo.cc:31:22: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
         if(a==21&&a>b&&a-b>=2||b==21&&b>a&&b-a>2){
            ~~~~~~~~~~^~~~~~~~
foo.cc:36:27: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
         else if(a>=21&&a>b&&a-b>=2||b>=21&&b>a&&b-a>=2){
                 ~~~~~~~~~~^~~~~~~~

[Hydro](https://hydro.ac)提供评测服务