View Compilation Error

0_0_17842357_21755.cpp: In function 'long long int solve(long long int)':
0_0_17842357_21755.cpp:28:10: error: 'i' was not declared in this scope
     for (i = 0;; i++) {
          ^
0_0_17842357_21755.cpp:40:10: error: 'i' was not declared in this scope
     for (i = 0;; i++) {
          ^