/in/foo.cc: In function 'int main()':
/in/foo.cc:69:42: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
    if(s[ST[j][i - 1]] > s[ST[j + (1 << i - 1)][i - 1]]) ST[j][i] = ST[j][i - 1];
                                        ~~^~~
/in/foo.cc:70:35: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
    else ST[j][i] = ST[j + (1 << i - 1)][i - 1];
                                 ~~^~~