/in/foo.cc: In function 'int main()':
/in/foo.cc:34:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
     cin>>s1+1;
          ~~^~
/in/foo.cc:35:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
     cin>>s2+1;
          ~~^~