View Compilation Error

0_0_15927536_7197.cpp: In function 'void ins()':
0_0_15927536_7197.cpp:10:25: error: 'strlen' was not declared in this scope
     int now=1,l=strlen(s);
                         ^
0_0_15927536_7197.cpp: In function 'void solve()':
0_0_15927536_7197.cpp:38:23: error: 'strlen' was not declared in this scope
     int k=1,l=strlen(m);
                       ^