/in/foo.cc: In function 'int main()':
/in/foo.cc:58:29: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
          march_1(s1, s3, i) && march_2(s1, s2, i)) {
          ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~
/in/foo.cc:62:36: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
                 march_1(s2, s3, i) && march_2(s2, s1, i)) {
                 ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~
/in/foo.cc:66:36: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
                 march_1(s3, s2, i) && march_2(s3, s1, i)) {
                 ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~